2hbd - Revision history

OCA at 09:31, 14 February 2024

2024-02-14T09:31:48Z

←Older revision		Revision as of 09:31, 14 February 2024
Line 3:		Line 3:
	<StructureSection load='2hbd' size='340' side='right'caption='[[2hbd]], [[Resolution\|resolution]] 2.20Å' scene=''>		<StructureSection load='2hbd' size='340' side='right'caption='[[2hbd]], [[Resolution\|resolution]] 2.20Å' scene=''>
	== Structural highlights ==		== Structural highlights ==
-	<table><tr><td colspan='2'>[[2hbd]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/~~Human Human~~]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2HBD OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2HBD FirstGlance]. <br>	+	<table><tr><td colspan='2'>[[2hbd]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2HBD OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2HBD FirstGlance]. <br>
-	</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand\|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene>, <scene name='pdbligand=MNC:METHYL+ISOCYANIDE'>MNC</scene></td></tr>	+	</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models\|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution\|Resolution]] 2.2Å</td></tr>
		+	<tr id='ligand'><td class="sblockLbl"><b>[[Ligand\|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene>, <scene name='pdbligand=MNC:METHYL+ISOCYANIDE'>MNC</scene></td></tr>
	<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=2hbd FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2hbd OCA], [https://pdbe.org/2hbd PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2hbd RCSB], [https://www.ebi.ac.uk/pdbsum/2hbd PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2hbd ProSAT]</span></td></tr>		<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=2hbd FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2hbd OCA], [https://pdbe.org/2hbd PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2hbd RCSB], [https://www.ebi.ac.uk/pdbsum/2hbd PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2hbd ProSAT]</span></td></tr>
	</table>		</table>
	== Disease ==		== Disease ==
-	[[https://www.uniprot.org/uniprot/HBA_HUMAN HBA_HUMAN]] Defects in HBA1 may be a cause of Heinz body anemias (HEIBAN) [MIM:[https://omim.org/entry/140700 140700]]. This is a form of non-spherocytic hemolytic anemia of Dacie type 1. After splenectomy, which has little benefit, basophilic inclusions called Heinz bodies are demonstrable in the erythrocytes. Before splenectomy, diffuse or punctate basophilia may be evident. Most of these cases are probably instances of hemoglobinopathy. The hemoglobin demonstrates heat lability. Heinz bodies are observed also with the Ivemark syndrome (asplenia with cardiovascular anomalies) and with glutathione peroxidase deficiency.<ref>PMID:2833478</ref> Defects in HBA1 are the cause of alpha-thalassemia (A-THAL) [MIM:[https://omim.org/entry/604131 604131]]. The thalassemias are the most common monogenic diseases and occur mostly in Mediterranean and Southeast Asian populations. The hallmark of alpha-thalassemia is an imbalance in globin-chain production in the adult HbA molecule. The level of alpha chain production can range from none to very nearly normal levels. Deletion of both copies of each of the two alpha-globin genes causes alpha(0)-thalassemia, also known as homozygous alpha thalassemia. Due to the complete absence of alpha chains, the predominant fetal hemoglobin is a tetramer of gamma-chains (Bart hemoglobin) that has essentially no oxygen carrying capacity. This causes oxygen starvation in the fetal tissues leading to prenatal lethality or early neonatal death. The loss of three alpha genes results in high levels of a tetramer of four beta chains (hemoglobin H), causing a severe and life-threatening anemia known as hemoglobin H disease. Untreated, most patients die in childhood or early adolescence. The loss of two alpha genes results in mild alpha-thalassemia, also known as heterozygous alpha-thalassemia. Affected individuals have small red cells and a mild anemia (microcytosis). If three of the four alpha-globin genes are functional, individuals are completely asymptomatic. Some rare forms of alpha-thalassemia are due to point mutations (non-deletional alpha-thalassemia). The thalassemic phenotype is due to unstable globin alpha chains that are rapidly catabolized prior to formation of the alpha-beta heterotetramers. Note=Alpha(0)-thalassemia is associated with non-immune hydrops fetalis, a generalized edema of the fetus with fluid accumulation in the body cavities due to non-immune causes. Non-immune hydrops fetalis is not a diagnosis in itself but a symptom, a feature of many genetic disorders, and the end-stage of a wide variety of disorders. Defects in HBA1 are the cause of hemoglobin H disease (HBH) [MIM:[https://omim.org/entry/613978 613978]]. HBH is a form of alpha-thalassemia due to the loss of three alpha genes. This results in high levels of a tetramer of four beta chains (hemoglobin H), causing a severe and life-threatening anemia. Untreated, most patients die in childhood or early adolescence.<ref>PMID:10569720</ref> [[https://www.uniprot.org/uniprot/HBB_HUMAN HBB_HUMAN]] Defects in HBB may be a cause of Heinz body anemias (HEIBAN) [MIM:[https://omim.org/entry/140700 140700]]. This is a form of non-spherocytic hemolytic anemia of Dacie type 1. After splenectomy, which has little benefit, basophilic inclusions called Heinz bodies are demonstrable in the erythrocytes. Before splenectomy, diffuse or punctate basophilia may be evident. Most of these cases are probably instances of hemoglobinopathy. The hemoglobin demonstrates heat lability. Heinz bodies are observed also with the Ivemark syndrome (asplenia with cardiovascular anomalies) and with glutathione peroxidase deficiency.<ref>PMID:186485</ref> <ref>PMID:6259091</ref> <ref>PMID:2599881</ref> <ref>PMID:8704193</ref> Defects in HBB are the cause of beta-thalassemia (B-THAL) [MIM:[https://omim.org/entry/613985 613985]]. A form of thalassemia. Thalassemias are common monogenic diseases occurring mostly in Mediterranean and Southeast Asian populations. The hallmark of beta-thalassemia is an imbalance in globin-chain production in the adult HbA molecule. Absence of beta chain causes beta(0)-thalassemia, while reduced amounts of detectable beta globin causes beta(+)-thalassemia. In the severe forms of beta-thalassemia, the excess alpha globin chains accumulate in the developing erythroid precursors in the marrow. Their deposition leads to a vast increase in erythroid apoptosis that in turn causes ineffective erythropoiesis and severe microcytic hypochromic anemia. Clinically, beta-thalassemia is divided into thalassemia major which is transfusion dependent, thalassemia intermedia (of intermediate severity), and thalassemia minor that is asymptomatic.<ref>PMID:1971109</ref> Defects in HBB are the cause of sickle cell anemia (SKCA) [MIM:[https://omim.org/entry/603903 603903]]; also known as sickle cell disease. Sickle cell anemia is characterized by abnormally shaped red cells resulting in chronic anemia and periodic episodes of pain, serious infections and damage to vital organs. Normal red blood cells are round and flexible and flow easily through blood vessels, but in sickle cell anemia, the abnormal hemoglobin (called Hb S) causes red blood cells to become stiff. They are C-shaped and resembles a sickle. These stiffer red blood cells can led to microvascular occlusion thus cutting off the blood supply to nearby tissues. Defects in HBB are the cause of beta-thalassemia dominant inclusion body type (B-THALIB) [MIM:[https://omim.org/entry/603902 603902]]. An autosomal dominant form of beta thalassemia characterized by moderate anemia, lifelong jaundice, cholelithiasis and splenomegaly, marked morphologic changes in the red cells, erythroid hyperplasia of the bone marrow with increased numbers of multinucleate red cell precursors, and the presence of large inclusion bodies in the normoblasts, both in the marrow and in the peripheral blood after splenectomy.<ref>PMID:1971109</ref>	+	[https://www.uniprot.org/uniprot/HBA_HUMAN HBA_HUMAN] Defects in HBA1 may be a cause of Heinz body anemias (HEIBAN) [MIM:[https://omim.org/entry/140700 140700]. This is a form of non-spherocytic hemolytic anemia of Dacie type 1. After splenectomy, which has little benefit, basophilic inclusions called Heinz bodies are demonstrable in the erythrocytes. Before splenectomy, diffuse or punctate basophilia may be evident. Most of these cases are probably instances of hemoglobinopathy. The hemoglobin demonstrates heat lability. Heinz bodies are observed also with the Ivemark syndrome (asplenia with cardiovascular anomalies) and with glutathione peroxidase deficiency.<ref>PMID:2833478</ref> Defects in HBA1 are the cause of alpha-thalassemia (A-THAL) [MIM:[https://omim.org/entry/604131 604131]. The thalassemias are the most common monogenic diseases and occur mostly in Mediterranean and Southeast Asian populations. The hallmark of alpha-thalassemia is an imbalance in globin-chain production in the adult HbA molecule. The level of alpha chain production can range from none to very nearly normal levels. Deletion of both copies of each of the two alpha-globin genes causes alpha(0)-thalassemia, also known as homozygous alpha thalassemia. Due to the complete absence of alpha chains, the predominant fetal hemoglobin is a tetramer of gamma-chains (Bart hemoglobin) that has essentially no oxygen carrying capacity. This causes oxygen starvation in the fetal tissues leading to prenatal lethality or early neonatal death. The loss of three alpha genes results in high levels of a tetramer of four beta chains (hemoglobin H), causing a severe and life-threatening anemia known as hemoglobin H disease. Untreated, most patients die in childhood or early adolescence. The loss of two alpha genes results in mild alpha-thalassemia, also known as heterozygous alpha-thalassemia. Affected individuals have small red cells and a mild anemia (microcytosis). If three of the four alpha-globin genes are functional, individuals are completely asymptomatic. Some rare forms of alpha-thalassemia are due to point mutations (non-deletional alpha-thalassemia). The thalassemic phenotype is due to unstable globin alpha chains that are rapidly catabolized prior to formation of the alpha-beta heterotetramers. Note=Alpha(0)-thalassemia is associated with non-immune hydrops fetalis, a generalized edema of the fetus with fluid accumulation in the body cavities due to non-immune causes. Non-immune hydrops fetalis is not a diagnosis in itself but a symptom, a feature of many genetic disorders, and the end-stage of a wide variety of disorders. Defects in HBA1 are the cause of hemoglobin H disease (HBH) [MIM:[https://omim.org/entry/613978 613978]. HBH is a form of alpha-thalassemia due to the loss of three alpha genes. This results in high levels of a tetramer of four beta chains (hemoglobin H), causing a severe and life-threatening anemia. Untreated, most patients die in childhood or early adolescence.<ref>PMID:10569720</ref>
	== Function ==		== Function ==
-	[[https://www.uniprot.org/uniprot/HBA_HUMAN HBA_HUMAN]] Involved in oxygen transport from the lung to the various peripheral tissues. [[https://www.uniprot.org/uniprot/HBB_HUMAN HBB_HUMAN]] Involved in oxygen transport from the lung to the various peripheral tissues.<ref>PMID:16904236</ref> LVV-hemorphin-7 potentiates the activity of bradykinin, causing a decrease in blood pressure.<ref>PMID:16904236</ref>	+	[https://www.uniprot.org/uniprot/HBA_HUMAN HBA_HUMAN] Involved in oxygen transport from the lung to the various peripheral tissues.
	== Evolutionary Conservation ==		== Evolutionary Conservation ==
	[[Image:Consurf_key_small.gif\|200px\|right]]		[[Image:Consurf_key_small.gif\|200px\|right]]
Line 28:		Line 29:
	__TOC__		__TOC__
	</StructureSection>		</StructureSection>
-	[[Category: ~~Human~~]]	+	[[Category: Homo sapiens]]
	[[Category: Large Structures]]		[[Category: Large Structures]]
-	[[Category: Johnson~~, K A~~]]	+	[[Category: Johnson KA]]
-	[[Category: Olson~~, J S~~]]	+	[[Category: Olson JS]]
-	[[Category: Phillips~~, G N]]~~	+	[[Category: Phillips Jr GN]]
-	~~[[Category: Oxygen transport~~]]	+

OCA at 20:41, 20 October 2021

2021-10-20T20:41:32Z

←Older revision		Revision as of 20:41, 20 October 2021
Line 3:		Line 3:
	<StructureSection load='2hbd' size='340' side='right'caption='[[2hbd]], [[Resolution\|resolution]] 2.20Å' scene=''>		<StructureSection load='2hbd' size='340' side='right'caption='[[2hbd]], [[Resolution\|resolution]] 2.20Å' scene=''>
	== Structural highlights ==		== Structural highlights ==
-	<table><tr><td colspan='2'>[[2hbd]] is a 2 chain structure with sequence from [~~http~~://en.wikipedia.org/wiki/Human Human]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2HBD OCA]. For a <b>guided tour on the structure components</b> use [~~http~~://~~oca~~.~~weizmann.ac.il/oca-docs~~/fgij/fg.htm?mol=2HBD FirstGlance]. <br>	+	<table><tr><td colspan='2'>[[2hbd]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Human Human]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2HBD OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2HBD FirstGlance]. <br>
-	</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand\|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene>, <scene name='pdbligand=MNC:METHYL+ISOCYANIDE'>MNC</scene></td></tr>	+	</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand\|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene>, <scene name='pdbligand=MNC:METHYL+ISOCYANIDE'>MNC</scene></td></tr>
-	<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[~~http~~://~~oca~~.~~weizmann.ac.il/oca-docs~~/fgij/fg.htm?mol=2hbd FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2hbd OCA], [~~http~~://pdbe.org/2hbd PDBe], [~~http~~://www.rcsb.org/pdb/explore.do?structureId=2hbd RCSB], [~~http~~://www.ebi.ac.uk/pdbsum/2hbd PDBsum], [~~http~~://prosat.h-its.org/prosat/prosatexe?pdbcode=2hbd ProSAT]</span></td></tr>	+	<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=2hbd FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2hbd OCA], [https://pdbe.org/2hbd PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2hbd RCSB], [https://www.ebi.ac.uk/pdbsum/2hbd PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2hbd ProSAT]</span></td></tr>
	</table>		</table>
	== Disease ==		== Disease ==
-	[[~~http~~://www.uniprot.org/uniprot/HBA_HUMAN HBA_HUMAN]] Defects in HBA1 may be a cause of Heinz body anemias (HEIBAN) [MIM:[~~http~~://omim.org/entry/140700 140700]]. This is a form of non-spherocytic hemolytic anemia of Dacie type 1. After splenectomy, which has little benefit, basophilic inclusions called Heinz bodies are demonstrable in the erythrocytes. Before splenectomy, diffuse or punctate basophilia may be evident. Most of these cases are probably instances of hemoglobinopathy. The hemoglobin demonstrates heat lability. Heinz bodies are observed also with the Ivemark syndrome (asplenia with cardiovascular anomalies) and with glutathione peroxidase deficiency.<ref>PMID:2833478</ref> Defects in HBA1 are the cause of alpha-thalassemia (A-THAL) [MIM:[~~http~~://omim.org/entry/604131 604131]]. The thalassemias are the most common monogenic diseases and occur mostly in Mediterranean and Southeast Asian populations. The hallmark of alpha-thalassemia is an imbalance in globin-chain production in the adult HbA molecule. The level of alpha chain production can range from none to very nearly normal levels. Deletion of both copies of each of the two alpha-globin genes causes alpha(0)-thalassemia, also known as homozygous alpha thalassemia. Due to the complete absence of alpha chains, the predominant fetal hemoglobin is a tetramer of gamma-chains (Bart hemoglobin) that has essentially no oxygen carrying capacity. This causes oxygen starvation in the fetal tissues leading to prenatal lethality or early neonatal death. The loss of three alpha genes results in high levels of a tetramer of four beta chains (hemoglobin H), causing a severe and life-threatening anemia known as hemoglobin H disease. Untreated, most patients die in childhood or early adolescence. The loss of two alpha genes results in mild alpha-thalassemia, also known as heterozygous alpha-thalassemia. Affected individuals have small red cells and a mild anemia (microcytosis). If three of the four alpha-globin genes are functional, individuals are completely asymptomatic. Some rare forms of alpha-thalassemia are due to point mutations (non-deletional alpha-thalassemia). The thalassemic phenotype is due to unstable globin alpha chains that are rapidly catabolized prior to formation of the alpha-beta heterotetramers. Note=Alpha(0)-thalassemia is associated with non-immune hydrops fetalis, a generalized edema of the fetus with fluid accumulation in the body cavities due to non-immune causes. Non-immune hydrops fetalis is not a diagnosis in itself but a symptom, a feature of many genetic disorders, and the end-stage of a wide variety of disorders. Defects in HBA1 are the cause of hemoglobin H disease (HBH) [MIM:[~~http~~://omim.org/entry/613978 613978]]. HBH is a form of alpha-thalassemia due to the loss of three alpha genes. This results in high levels of a tetramer of four beta chains (hemoglobin H), causing a severe and life-threatening anemia. Untreated, most patients die in childhood or early adolescence.<ref>PMID:10569720</ref> [[~~http~~://www.uniprot.org/uniprot/HBB_HUMAN HBB_HUMAN]] Defects in HBB may be a cause of Heinz body anemias (HEIBAN) [MIM:[~~http~~://omim.org/entry/140700 140700]]. This is a form of non-spherocytic hemolytic anemia of Dacie type 1. After splenectomy, which has little benefit, basophilic inclusions called Heinz bodies are demonstrable in the erythrocytes. Before splenectomy, diffuse or punctate basophilia may be evident. Most of these cases are probably instances of hemoglobinopathy. The hemoglobin demonstrates heat lability. Heinz bodies are observed also with the Ivemark syndrome (asplenia with cardiovascular anomalies) and with glutathione peroxidase deficiency.<ref>PMID:186485</ref> <ref>PMID:6259091</ref> <ref>PMID:2599881</ref> <ref>PMID:8704193</ref> Defects in HBB are the cause of beta-thalassemia (B-THAL) [MIM:[~~http~~://omim.org/entry/613985 613985]]. A form of thalassemia. Thalassemias are common monogenic diseases occurring mostly in Mediterranean and Southeast Asian populations. The hallmark of beta-thalassemia is an imbalance in globin-chain production in the adult HbA molecule. Absence of beta chain causes beta(0)-thalassemia, while reduced amounts of detectable beta globin causes beta(+)-thalassemia. In the severe forms of beta-thalassemia, the excess alpha globin chains accumulate in the developing erythroid precursors in the marrow. Their deposition leads to a vast increase in erythroid apoptosis that in turn causes ineffective erythropoiesis and severe microcytic hypochromic anemia. Clinically, beta-thalassemia is divided into thalassemia major which is transfusion dependent, thalassemia intermedia (of intermediate severity), and thalassemia minor that is asymptomatic.<ref>PMID:1971109</ref> Defects in HBB are the cause of sickle cell anemia (SKCA) [MIM:[~~http~~://omim.org/entry/603903 603903]]; also known as sickle cell disease. Sickle cell anemia is characterized by abnormally shaped red cells resulting in chronic anemia and periodic episodes of pain, serious infections and damage to vital organs. Normal red blood cells are round and flexible and flow easily through blood vessels, but in sickle cell anemia, the abnormal hemoglobin (called Hb S) causes red blood cells to become stiff. They are C-shaped and resembles a sickle. These stiffer red blood cells can led to microvascular occlusion thus cutting off the blood supply to nearby tissues. Defects in HBB are the cause of beta-thalassemia dominant inclusion body type (B-THALIB) [MIM:[~~http~~://omim.org/entry/603902 603902]]. An autosomal dominant form of beta thalassemia characterized by moderate anemia, lifelong jaundice, cholelithiasis and splenomegaly, marked morphologic changes in the red cells, erythroid hyperplasia of the bone marrow with increased numbers of multinucleate red cell precursors, and the presence of large inclusion bodies in the normoblasts, both in the marrow and in the peripheral blood after splenectomy.<ref>PMID:1971109</ref>	+	[[https://www.uniprot.org/uniprot/HBA_HUMAN HBA_HUMAN]] Defects in HBA1 may be a cause of Heinz body anemias (HEIBAN) [MIM:[https://omim.org/entry/140700 140700]]. This is a form of non-spherocytic hemolytic anemia of Dacie type 1. After splenectomy, which has little benefit, basophilic inclusions called Heinz bodies are demonstrable in the erythrocytes. Before splenectomy, diffuse or punctate basophilia may be evident. Most of these cases are probably instances of hemoglobinopathy. The hemoglobin demonstrates heat lability. Heinz bodies are observed also with the Ivemark syndrome (asplenia with cardiovascular anomalies) and with glutathione peroxidase deficiency.<ref>PMID:2833478</ref> Defects in HBA1 are the cause of alpha-thalassemia (A-THAL) [MIM:[https://omim.org/entry/604131 604131]]. The thalassemias are the most common monogenic diseases and occur mostly in Mediterranean and Southeast Asian populations. The hallmark of alpha-thalassemia is an imbalance in globin-chain production in the adult HbA molecule. The level of alpha chain production can range from none to very nearly normal levels. Deletion of both copies of each of the two alpha-globin genes causes alpha(0)-thalassemia, also known as homozygous alpha thalassemia. Due to the complete absence of alpha chains, the predominant fetal hemoglobin is a tetramer of gamma-chains (Bart hemoglobin) that has essentially no oxygen carrying capacity. This causes oxygen starvation in the fetal tissues leading to prenatal lethality or early neonatal death. The loss of three alpha genes results in high levels of a tetramer of four beta chains (hemoglobin H), causing a severe and life-threatening anemia known as hemoglobin H disease. Untreated, most patients die in childhood or early adolescence. The loss of two alpha genes results in mild alpha-thalassemia, also known as heterozygous alpha-thalassemia. Affected individuals have small red cells and a mild anemia (microcytosis). If three of the four alpha-globin genes are functional, individuals are completely asymptomatic. Some rare forms of alpha-thalassemia are due to point mutations (non-deletional alpha-thalassemia). The thalassemic phenotype is due to unstable globin alpha chains that are rapidly catabolized prior to formation of the alpha-beta heterotetramers. Note=Alpha(0)-thalassemia is associated with non-immune hydrops fetalis, a generalized edema of the fetus with fluid accumulation in the body cavities due to non-immune causes. Non-immune hydrops fetalis is not a diagnosis in itself but a symptom, a feature of many genetic disorders, and the end-stage of a wide variety of disorders. Defects in HBA1 are the cause of hemoglobin H disease (HBH) [MIM:[https://omim.org/entry/613978 613978]]. HBH is a form of alpha-thalassemia due to the loss of three alpha genes. This results in high levels of a tetramer of four beta chains (hemoglobin H), causing a severe and life-threatening anemia. Untreated, most patients die in childhood or early adolescence.<ref>PMID:10569720</ref> [[https://www.uniprot.org/uniprot/HBB_HUMAN HBB_HUMAN]] Defects in HBB may be a cause of Heinz body anemias (HEIBAN) [MIM:[https://omim.org/entry/140700 140700]]. This is a form of non-spherocytic hemolytic anemia of Dacie type 1. After splenectomy, which has little benefit, basophilic inclusions called Heinz bodies are demonstrable in the erythrocytes. Before splenectomy, diffuse or punctate basophilia may be evident. Most of these cases are probably instances of hemoglobinopathy. The hemoglobin demonstrates heat lability. Heinz bodies are observed also with the Ivemark syndrome (asplenia with cardiovascular anomalies) and with glutathione peroxidase deficiency.<ref>PMID:186485</ref> <ref>PMID:6259091</ref> <ref>PMID:2599881</ref> <ref>PMID:8704193</ref> Defects in HBB are the cause of beta-thalassemia (B-THAL) [MIM:[https://omim.org/entry/613985 613985]]. A form of thalassemia. Thalassemias are common monogenic diseases occurring mostly in Mediterranean and Southeast Asian populations. The hallmark of beta-thalassemia is an imbalance in globin-chain production in the adult HbA molecule. Absence of beta chain causes beta(0)-thalassemia, while reduced amounts of detectable beta globin causes beta(+)-thalassemia. In the severe forms of beta-thalassemia, the excess alpha globin chains accumulate in the developing erythroid precursors in the marrow. Their deposition leads to a vast increase in erythroid apoptosis that in turn causes ineffective erythropoiesis and severe microcytic hypochromic anemia. Clinically, beta-thalassemia is divided into thalassemia major which is transfusion dependent, thalassemia intermedia (of intermediate severity), and thalassemia minor that is asymptomatic.<ref>PMID:1971109</ref> Defects in HBB are the cause of sickle cell anemia (SKCA) [MIM:[https://omim.org/entry/603903 603903]]; also known as sickle cell disease. Sickle cell anemia is characterized by abnormally shaped red cells resulting in chronic anemia and periodic episodes of pain, serious infections and damage to vital organs. Normal red blood cells are round and flexible and flow easily through blood vessels, but in sickle cell anemia, the abnormal hemoglobin (called Hb S) causes red blood cells to become stiff. They are C-shaped and resembles a sickle. These stiffer red blood cells can led to microvascular occlusion thus cutting off the blood supply to nearby tissues. Defects in HBB are the cause of beta-thalassemia dominant inclusion body type (B-THALIB) [MIM:[https://omim.org/entry/603902 603902]]. An autosomal dominant form of beta thalassemia characterized by moderate anemia, lifelong jaundice, cholelithiasis and splenomegaly, marked morphologic changes in the red cells, erythroid hyperplasia of the bone marrow with increased numbers of multinucleate red cell precursors, and the presence of large inclusion bodies in the normoblasts, both in the marrow and in the peripheral blood after splenectomy.<ref>PMID:1971109</ref>
	== Function ==		== Function ==
-	[[~~http~~://www.uniprot.org/uniprot/HBA_HUMAN HBA_HUMAN]] Involved in oxygen transport from the lung to the various peripheral tissues. [[~~http~~://www.uniprot.org/uniprot/HBB_HUMAN HBB_HUMAN]] Involved in oxygen transport from the lung to the various peripheral tissues.<ref>PMID:16904236</ref> LVV-hemorphin-7 potentiates the activity of bradykinin, causing a decrease in blood pressure.<ref>PMID:16904236</ref>	+	[[https://www.uniprot.org/uniprot/HBA_HUMAN HBA_HUMAN]] Involved in oxygen transport from the lung to the various peripheral tissues. [[https://www.uniprot.org/uniprot/HBB_HUMAN HBB_HUMAN]] Involved in oxygen transport from the lung to the various peripheral tissues.<ref>PMID:16904236</ref> LVV-hemorphin-7 potentiates the activity of bradykinin, causing a decrease in blood pressure.<ref>PMID:16904236</ref>
	== Evolutionary Conservation ==		== Evolutionary Conservation ==
	[[Image:Consurf_key_small.gif\|200px\|right]]		[[Image:Consurf_key_small.gif\|200px\|right]]

OCA at 07:12, 27 November 2019

2019-11-27T07:12:40Z

←Older revision		Revision as of 07:12, 27 November 2019
Line 1:		Line 1:

	==HIGH RESOLUTION X-RAY STRUCTURES OF MYOGLOBIN-AND HEMOGLOBIN-ALKYL ISOCYANIDE COMPLEXES==		==HIGH RESOLUTION X-RAY STRUCTURES OF MYOGLOBIN-AND HEMOGLOBIN-ALKYL ISOCYANIDE COMPLEXES==
-	<StructureSection load='2hbd' size='340' side='right' caption='[[2hbd]], [[Resolution\|resolution]] 2.20Å' scene=''>	+	<StructureSection load='2hbd' size='340' side='right'caption='[[2hbd]], [[Resolution\|resolution]] 2.20Å' scene=''>
	== Structural highlights ==		== Structural highlights ==
	<table><tr><td colspan='2'>[[2hbd]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Human Human]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2HBD OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2HBD FirstGlance]. <br>		<table><tr><td colspan='2'>[[2hbd]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Human Human]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2HBD OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2HBD FirstGlance]. <br>
Line 29:		Line 29:
	</StructureSection>		</StructureSection>
	[[Category: Human]]		[[Category: Human]]
		+	[[Category: Large Structures]]
	[[Category: Johnson, K A]]		[[Category: Johnson, K A]]
	[[Category: Olson, J S]]		[[Category: Olson, J S]]
	[[Category: Phillips, G N]]		[[Category: Phillips, G N]]
	[[Category: Oxygen transport]]		[[Category: Oxygen transport]]

OCA at 06:33, 27 June 2018

2018-06-27T06:33:21Z

←Older revision		Revision as of 06:33, 27 June 2018
Line 1:		Line 1:
		+
	==HIGH RESOLUTION X-RAY STRUCTURES OF MYOGLOBIN-AND HEMOGLOBIN-ALKYL ISOCYANIDE COMPLEXES==		==HIGH RESOLUTION X-RAY STRUCTURES OF MYOGLOBIN-AND HEMOGLOBIN-ALKYL ISOCYANIDE COMPLEXES==
	<StructureSection load='2hbd' size='340' side='right' caption='[[2hbd]], [[Resolution\|resolution]] 2.20Å' scene=''>		<StructureSection load='2hbd' size='340' side='right' caption='[[2hbd]], [[Resolution\|resolution]] 2.20Å' scene=''>
Line 4:		Line 5:
	<table><tr><td colspan='2'>[[2hbd]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Human Human]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2HBD OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2HBD FirstGlance]. <br>		<table><tr><td colspan='2'>[[2hbd]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Human Human]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2HBD OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2HBD FirstGlance]. <br>
	</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand\|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene>, <scene name='pdbligand=MNC:METHYL+ISOCYANIDE'>MNC</scene></td></tr>		</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand\|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene>, <scene name='pdbligand=MNC:METHYL+ISOCYANIDE'>MNC</scene></td></tr>
-	<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2hbd FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2hbd OCA], [http://pdbe.org/2hbd PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=2hbd RCSB], [http://www.ebi.ac.uk/pdbsum/2hbd PDBsum]</span></td></tr>	+	<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2hbd FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2hbd OCA], [http://pdbe.org/2hbd PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=2hbd RCSB], [http://www.ebi.ac.uk/pdbsum/2hbd PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=2hbd ProSAT]</span></td></tr>
	</table>		</table>
	== Disease ==		== Disease ==
Line 14:		Line 15:
	Check<jmol>		Check<jmol>
	<jmolCheckbox>		<jmolCheckbox>
-	<scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/hb/2hbd_consurf.spt"</scriptWhenChecked>	+	<scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/hb/2hbd_consurf.spt"</scriptWhenChecked>
	<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>		<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
	<text>to colour the structure by Evolutionary Conservation</text>		<text>to colour the structure by Evolutionary Conservation</text>

OCA at 08:09, 10 February 2016

2016-02-10T08:09:04Z

←Older revision		Revision as of 08:09, 10 February 2016
Line 18:		Line 18:
	<text>to colour the structure by Evolutionary Conservation</text>		<text>to colour the structure by Evolutionary Conservation</text>
	</jmolCheckbox>		</jmolCheckbox>
-	</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary\|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/~~chain_selection~~.php?pdb_ID=~~2ata~~ ConSurf].	+	</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary\|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=2hbd ConSurf].
	<div style="clear:both"></div>		<div style="clear:both"></div>

OCA at 06:59, 11 September 2015

2015-09-11T06:59:17Z

←Older revision		Revision as of 06:59, 11 September 2015
Line 2:		Line 2:
	<StructureSection load='2hbd' size='340' side='right' caption='[[2hbd]], [[Resolution\|resolution]] 2.20Å' scene=''>		<StructureSection load='2hbd' size='340' side='right' caption='[[2hbd]], [[Resolution\|resolution]] 2.20Å' scene=''>
	== Structural highlights ==		== Structural highlights ==
-	<table><tr><td colspan='2'>[[2hbd]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/~~Homo_sapiens Homo sapiens~~]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2HBD OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2HBD FirstGlance]. <br>	+	<table><tr><td colspan='2'>[[2hbd]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Human Human]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2HBD OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2HBD FirstGlance]. <br>
	</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand\|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene>, <scene name='pdbligand=MNC:METHYL+ISOCYANIDE'>MNC</scene></td></tr>		</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand\|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene>, <scene name='pdbligand=MNC:METHYL+ISOCYANIDE'>MNC</scene></td></tr>
-	<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2hbd FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2hbd OCA], [http://www.rcsb.org/pdb/explore.do?structureId=2hbd RCSB], [http://www.ebi.ac.uk/pdbsum/2hbd PDBsum]</span></td></tr>	+	<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2hbd FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2hbd OCA], [http://pdbe.org/2hbd PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=2hbd RCSB], [http://www.ebi.ac.uk/pdbsum/2hbd PDBsum]</span></td></tr>
	</table>		</table>
	== Disease ==		== Disease ==
Line 27:		Line 27:
	__TOC__		__TOC__
	</StructureSection>		</StructureSection>
-	[[Category: ~~Homo sapiens~~]]	+	[[Category: Human]]
	[[Category: Johnson, K A]]		[[Category: Johnson, K A]]
	[[Category: Olson, J S]]		[[Category: Olson, J S]]
	[[Category: Phillips, G N]]		[[Category: Phillips, G N]]
	[[Category: Oxygen transport]]		[[Category: Oxygen transport]]

OCA at 09:09, 16 January 2015

2015-01-16T09:09:42Z

←Older revision		Revision as of 09:09, 16 January 2015
Line 3:		Line 3:
	== Structural highlights ==		== Structural highlights ==
	<table><tr><td colspan='2'>[[2hbd]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2HBD OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2HBD FirstGlance]. <br>		<table><tr><td colspan='2'>[[2hbd]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2HBD OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2HBD FirstGlance]. <br>
-	</td></tr><tr><td class="sblockLbl"><b>[[Ligand\|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene>, <scene name='pdbligand=MNC:METHYL+ISOCYANIDE'>MNC</scene><br>	+	</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand\|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene>, <scene name='pdbligand=MNC:METHYL+ISOCYANIDE'>MNC</scene></td></tr>
-	<tr><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2hbd FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2hbd OCA], [http://www.rcsb.org/pdb/explore.do?structureId=2hbd RCSB], [http://www.ebi.ac.uk/pdbsum/2hbd PDBsum]</span></td></tr>	+	<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2hbd FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2hbd OCA], [http://www.rcsb.org/pdb/explore.do?structureId=2hbd RCSB], [http://www.ebi.ac.uk/pdbsum/2hbd PDBsum]</span></td></tr>
-	<table>	+	</table>
	== Disease ==		== Disease ==
	[[http://www.uniprot.org/uniprot/HBA_HUMAN HBA_HUMAN]] Defects in HBA1 may be a cause of Heinz body anemias (HEIBAN) [MIM:[http://omim.org/entry/140700 140700]]. This is a form of non-spherocytic hemolytic anemia of Dacie type 1. After splenectomy, which has little benefit, basophilic inclusions called Heinz bodies are demonstrable in the erythrocytes. Before splenectomy, diffuse or punctate basophilia may be evident. Most of these cases are probably instances of hemoglobinopathy. The hemoglobin demonstrates heat lability. Heinz bodies are observed also with the Ivemark syndrome (asplenia with cardiovascular anomalies) and with glutathione peroxidase deficiency.<ref>PMID:2833478</ref> Defects in HBA1 are the cause of alpha-thalassemia (A-THAL) [MIM:[http://omim.org/entry/604131 604131]]. The thalassemias are the most common monogenic diseases and occur mostly in Mediterranean and Southeast Asian populations. The hallmark of alpha-thalassemia is an imbalance in globin-chain production in the adult HbA molecule. The level of alpha chain production can range from none to very nearly normal levels. Deletion of both copies of each of the two alpha-globin genes causes alpha(0)-thalassemia, also known as homozygous alpha thalassemia. Due to the complete absence of alpha chains, the predominant fetal hemoglobin is a tetramer of gamma-chains (Bart hemoglobin) that has essentially no oxygen carrying capacity. This causes oxygen starvation in the fetal tissues leading to prenatal lethality or early neonatal death. The loss of three alpha genes results in high levels of a tetramer of four beta chains (hemoglobin H), causing a severe and life-threatening anemia known as hemoglobin H disease. Untreated, most patients die in childhood or early adolescence. The loss of two alpha genes results in mild alpha-thalassemia, also known as heterozygous alpha-thalassemia. Affected individuals have small red cells and a mild anemia (microcytosis). If three of the four alpha-globin genes are functional, individuals are completely asymptomatic. Some rare forms of alpha-thalassemia are due to point mutations (non-deletional alpha-thalassemia). The thalassemic phenotype is due to unstable globin alpha chains that are rapidly catabolized prior to formation of the alpha-beta heterotetramers. Note=Alpha(0)-thalassemia is associated with non-immune hydrops fetalis, a generalized edema of the fetus with fluid accumulation in the body cavities due to non-immune causes. Non-immune hydrops fetalis is not a diagnosis in itself but a symptom, a feature of many genetic disorders, and the end-stage of a wide variety of disorders. Defects in HBA1 are the cause of hemoglobin H disease (HBH) [MIM:[http://omim.org/entry/613978 613978]]. HBH is a form of alpha-thalassemia due to the loss of three alpha genes. This results in high levels of a tetramer of four beta chains (hemoglobin H), causing a severe and life-threatening anemia. Untreated, most patients die in childhood or early adolescence.<ref>PMID:10569720</ref> [[http://www.uniprot.org/uniprot/HBB_HUMAN HBB_HUMAN]] Defects in HBB may be a cause of Heinz body anemias (HEIBAN) [MIM:[http://omim.org/entry/140700 140700]]. This is a form of non-spherocytic hemolytic anemia of Dacie type 1. After splenectomy, which has little benefit, basophilic inclusions called Heinz bodies are demonstrable in the erythrocytes. Before splenectomy, diffuse or punctate basophilia may be evident. Most of these cases are probably instances of hemoglobinopathy. The hemoglobin demonstrates heat lability. Heinz bodies are observed also with the Ivemark syndrome (asplenia with cardiovascular anomalies) and with glutathione peroxidase deficiency.<ref>PMID:186485</ref> <ref>PMID:6259091</ref> <ref>PMID:2599881</ref> <ref>PMID:8704193</ref> Defects in HBB are the cause of beta-thalassemia (B-THAL) [MIM:[http://omim.org/entry/613985 613985]]. A form of thalassemia. Thalassemias are common monogenic diseases occurring mostly in Mediterranean and Southeast Asian populations. The hallmark of beta-thalassemia is an imbalance in globin-chain production in the adult HbA molecule. Absence of beta chain causes beta(0)-thalassemia, while reduced amounts of detectable beta globin causes beta(+)-thalassemia. In the severe forms of beta-thalassemia, the excess alpha globin chains accumulate in the developing erythroid precursors in the marrow. Their deposition leads to a vast increase in erythroid apoptosis that in turn causes ineffective erythropoiesis and severe microcytic hypochromic anemia. Clinically, beta-thalassemia is divided into thalassemia major which is transfusion dependent, thalassemia intermedia (of intermediate severity), and thalassemia minor that is asymptomatic.<ref>PMID:1971109</ref> Defects in HBB are the cause of sickle cell anemia (SKCA) [MIM:[http://omim.org/entry/603903 603903]]; also known as sickle cell disease. Sickle cell anemia is characterized by abnormally shaped red cells resulting in chronic anemia and periodic episodes of pain, serious infections and damage to vital organs. Normal red blood cells are round and flexible and flow easily through blood vessels, but in sickle cell anemia, the abnormal hemoglobin (called Hb S) causes red blood cells to become stiff. They are C-shaped and resembles a sickle. These stiffer red blood cells can led to microvascular occlusion thus cutting off the blood supply to nearby tissues. Defects in HBB are the cause of beta-thalassemia dominant inclusion body type (B-THALIB) [MIM:[http://omim.org/entry/603902 603902]]. An autosomal dominant form of beta thalassemia characterized by moderate anemia, lifelong jaundice, cholelithiasis and splenomegaly, marked morphologic changes in the red cells, erythroid hyperplasia of the bone marrow with increased numbers of multinucleate red cell precursors, and the presence of large inclusion bodies in the normoblasts, both in the marrow and in the peripheral blood after splenectomy.<ref>PMID:1971109</ref>		[[http://www.uniprot.org/uniprot/HBA_HUMAN HBA_HUMAN]] Defects in HBA1 may be a cause of Heinz body anemias (HEIBAN) [MIM:[http://omim.org/entry/140700 140700]]. This is a form of non-spherocytic hemolytic anemia of Dacie type 1. After splenectomy, which has little benefit, basophilic inclusions called Heinz bodies are demonstrable in the erythrocytes. Before splenectomy, diffuse or punctate basophilia may be evident. Most of these cases are probably instances of hemoglobinopathy. The hemoglobin demonstrates heat lability. Heinz bodies are observed also with the Ivemark syndrome (asplenia with cardiovascular anomalies) and with glutathione peroxidase deficiency.<ref>PMID:2833478</ref> Defects in HBA1 are the cause of alpha-thalassemia (A-THAL) [MIM:[http://omim.org/entry/604131 604131]]. The thalassemias are the most common monogenic diseases and occur mostly in Mediterranean and Southeast Asian populations. The hallmark of alpha-thalassemia is an imbalance in globin-chain production in the adult HbA molecule. The level of alpha chain production can range from none to very nearly normal levels. Deletion of both copies of each of the two alpha-globin genes causes alpha(0)-thalassemia, also known as homozygous alpha thalassemia. Due to the complete absence of alpha chains, the predominant fetal hemoglobin is a tetramer of gamma-chains (Bart hemoglobin) that has essentially no oxygen carrying capacity. This causes oxygen starvation in the fetal tissues leading to prenatal lethality or early neonatal death. The loss of three alpha genes results in high levels of a tetramer of four beta chains (hemoglobin H), causing a severe and life-threatening anemia known as hemoglobin H disease. Untreated, most patients die in childhood or early adolescence. The loss of two alpha genes results in mild alpha-thalassemia, also known as heterozygous alpha-thalassemia. Affected individuals have small red cells and a mild anemia (microcytosis). If three of the four alpha-globin genes are functional, individuals are completely asymptomatic. Some rare forms of alpha-thalassemia are due to point mutations (non-deletional alpha-thalassemia). The thalassemic phenotype is due to unstable globin alpha chains that are rapidly catabolized prior to formation of the alpha-beta heterotetramers. Note=Alpha(0)-thalassemia is associated with non-immune hydrops fetalis, a generalized edema of the fetus with fluid accumulation in the body cavities due to non-immune causes. Non-immune hydrops fetalis is not a diagnosis in itself but a symptom, a feature of many genetic disorders, and the end-stage of a wide variety of disorders. Defects in HBA1 are the cause of hemoglobin H disease (HBH) [MIM:[http://omim.org/entry/613978 613978]]. HBH is a form of alpha-thalassemia due to the loss of three alpha genes. This results in high levels of a tetramer of four beta chains (hemoglobin H), causing a severe and life-threatening anemia. Untreated, most patients die in childhood or early adolescence.<ref>PMID:10569720</ref> [[http://www.uniprot.org/uniprot/HBB_HUMAN HBB_HUMAN]] Defects in HBB may be a cause of Heinz body anemias (HEIBAN) [MIM:[http://omim.org/entry/140700 140700]]. This is a form of non-spherocytic hemolytic anemia of Dacie type 1. After splenectomy, which has little benefit, basophilic inclusions called Heinz bodies are demonstrable in the erythrocytes. Before splenectomy, diffuse or punctate basophilia may be evident. Most of these cases are probably instances of hemoglobinopathy. The hemoglobin demonstrates heat lability. Heinz bodies are observed also with the Ivemark syndrome (asplenia with cardiovascular anomalies) and with glutathione peroxidase deficiency.<ref>PMID:186485</ref> <ref>PMID:6259091</ref> <ref>PMID:2599881</ref> <ref>PMID:8704193</ref> Defects in HBB are the cause of beta-thalassemia (B-THAL) [MIM:[http://omim.org/entry/613985 613985]]. A form of thalassemia. Thalassemias are common monogenic diseases occurring mostly in Mediterranean and Southeast Asian populations. The hallmark of beta-thalassemia is an imbalance in globin-chain production in the adult HbA molecule. Absence of beta chain causes beta(0)-thalassemia, while reduced amounts of detectable beta globin causes beta(+)-thalassemia. In the severe forms of beta-thalassemia, the excess alpha globin chains accumulate in the developing erythroid precursors in the marrow. Their deposition leads to a vast increase in erythroid apoptosis that in turn causes ineffective erythropoiesis and severe microcytic hypochromic anemia. Clinically, beta-thalassemia is divided into thalassemia major which is transfusion dependent, thalassemia intermedia (of intermediate severity), and thalassemia minor that is asymptomatic.<ref>PMID:1971109</ref> Defects in HBB are the cause of sickle cell anemia (SKCA) [MIM:[http://omim.org/entry/603903 603903]]; also known as sickle cell disease. Sickle cell anemia is characterized by abnormally shaped red cells resulting in chronic anemia and periodic episodes of pain, serious infections and damage to vital organs. Normal red blood cells are round and flexible and flow easily through blood vessels, but in sickle cell anemia, the abnormal hemoglobin (called Hb S) causes red blood cells to become stiff. They are C-shaped and resembles a sickle. These stiffer red blood cells can led to microvascular occlusion thus cutting off the blood supply to nearby tissues. Defects in HBB are the cause of beta-thalassemia dominant inclusion body type (B-THALIB) [MIM:[http://omim.org/entry/603902 603902]]. An autosomal dominant form of beta thalassemia characterized by moderate anemia, lifelong jaundice, cholelithiasis and splenomegaly, marked morphologic changes in the red cells, erythroid hyperplasia of the bone marrow with increased numbers of multinucleate red cell precursors, and the presence of large inclusion bodies in the normoblasts, both in the marrow and in the peripheral blood after splenectomy.<ref>PMID:1971109</ref>
Line 28:		Line 28:
	</StructureSection>		</StructureSection>
	[[Category: Homo sapiens]]		[[Category: Homo sapiens]]
-	[[Category: Johnson, K A.]]	+	[[Category: Johnson, K A]]
-	[[Category: Olson, J S.]]	+	[[Category: Olson, J S]]
-	[[Category: Phillips, G N.]]	+	[[Category: Phillips, G N]]
	[[Category: Oxygen transport]]		[[Category: Oxygen transport]]

OCA at 10:39, 30 September 2014

2014-09-30T10:39:37Z

←Older revision		Revision as of 10:39, 30 September 2014
Line 1:		Line 1:
-	~~{{STRUCTURE_2hbd\| PDB=2hbd \| SCENE= }}~~	+	==HIGH RESOLUTION X-RAY STRUCTURES OF MYOGLOBIN-AND HEMOGLOBIN-ALKYL ISOCYANIDE COMPLEXES==
-	===HIGH RESOLUTION X-RAY STRUCTURES OF MYOGLOBIN-AND HEMOGLOBIN-ALKYL ISOCYANIDE COMPLEXES===	+	<StructureSection load='2hbd' size='340' side='right' caption='[[2hbd]], [[Resolution\|resolution]] 2.20Å' scene=''>
-		+	== Structural highlights ==
-	==Disease==	+	<table><tr><td colspan='2'>[[2hbd]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2HBD OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2HBD FirstGlance]. <br>
-	[[http://www.uniprot.org/uniprot/HBA_HUMAN HBA_HUMAN]] Defects in HBA1 may be a cause of Heinz body anemias (HEIBAN) [MIM:[http://omim.org/entry/140700 140700]]. This is a form of non-spherocytic hemolytic anemia of Dacie type 1. After splenectomy, which has little benefit, basophilic inclusions called Heinz bodies are demonstrable in the erythrocytes. Before splenectomy, diffuse or punctate basophilia may be evident. Most of these cases are probably instances of hemoglobinopathy. The hemoglobin demonstrates heat lability. Heinz bodies are observed also with the Ivemark syndrome (asplenia with cardiovascular anomalies) and with glutathione peroxidase deficiency.<ref>PMID:2833478</ref> Defects in HBA1 are the cause of alpha-thalassemia (A-THAL) [MIM:[http://omim.org/entry/604131 604131]]. The thalassemias are the most common monogenic diseases and occur mostly in Mediterranean and Southeast Asian populations. The hallmark of alpha-thalassemia is an imbalance in globin-chain production in the adult HbA molecule. The level of alpha chain production can range from none to very nearly normal levels. Deletion of both copies of each of the two alpha-globin genes causes alpha(0)-thalassemia, also known as homozygous alpha thalassemia. Due to the complete absence of alpha chains, the predominant fetal hemoglobin is a tetramer of gamma-chains (Bart hemoglobin) that has essentially no oxygen carrying capacity. This causes oxygen starvation in the fetal tissues leading to prenatal lethality or early neonatal death. The loss of three alpha genes results in high levels of a tetramer of four beta chains (hemoglobin H), causing a severe and life-threatening anemia known as hemoglobin H disease. Untreated, most patients die in childhood or early adolescence. The loss of two alpha genes results in mild alpha-thalassemia, also known as heterozygous alpha-thalassemia. Affected individuals have small red cells and a mild anemia (microcytosis). If three of the four alpha-globin genes are functional, individuals are completely asymptomatic. Some rare forms of alpha-thalassemia are due to point mutations (non-deletional alpha-thalassemia). The thalassemic phenotype is due to unstable globin alpha chains that are rapidly catabolized prior to formation of the alpha-beta heterotetramers. Note=Alpha(0)-thalassemia is associated with non-immune hydrops fetalis, a generalized edema of the fetus with fluid accumulation in the body cavities due to non-immune causes. Non-immune hydrops fetalis is not a diagnosis in itself but a symptom, a feature of many genetic disorders, and the end-stage of a wide variety of disorders. Defects in HBA1 are the cause of hemoglobin H disease (HBH) [MIM:[http://omim.org/entry/613978 613978]]. HBH is a form of alpha-thalassemia due to the loss of three alpha genes. This results in high levels of a tetramer of four beta chains (hemoglobin H), causing a severe and life-threatening anemia. Untreated, most patients die in childhood or early adolescence.<ref>PMID:10569720</ref> [[http://www.uniprot.org/uniprot/HBB_HUMAN HBB_HUMAN]] Defects in HBB may be a cause of Heinz body anemias (HEIBAN) [MIM:[http://omim.org/entry/140700 140700]]. This is a form of non-spherocytic hemolytic anemia of Dacie type 1. After splenectomy, which has little benefit, basophilic inclusions called Heinz bodies are demonstrable in the erythrocytes. Before splenectomy, diffuse or punctate basophilia may be evident. Most of these cases are probably instances of hemoglobinopathy. The hemoglobin demonstrates heat lability. Heinz bodies are observed also with the Ivemark syndrome (asplenia with cardiovascular anomalies) and with glutathione peroxidase deficiency.<ref>PMID:186485</ref><ref>PMID:6259091</ref><ref>PMID:2599881</ref><ref>PMID:8704193</ref> Defects in HBB are the cause of beta-thalassemia (B-THAL) [MIM:[http://omim.org/entry/613985 613985]]. A form of thalassemia. Thalassemias are common monogenic diseases occurring mostly in Mediterranean and Southeast Asian populations. The hallmark of beta-thalassemia is an imbalance in globin-chain production in the adult HbA molecule. Absence of beta chain causes beta(0)-thalassemia, while reduced amounts of detectable beta globin causes beta(+)-thalassemia. In the severe forms of beta-thalassemia, the excess alpha globin chains accumulate in the developing erythroid precursors in the marrow. Their deposition leads to a vast increase in erythroid apoptosis that in turn causes ineffective erythropoiesis and severe microcytic hypochromic anemia. Clinically, beta-thalassemia is divided into thalassemia major which is transfusion dependent, thalassemia intermedia (of intermediate severity), and thalassemia minor that is asymptomatic.<ref>PMID:1971109</ref> Defects in HBB are the cause of sickle cell anemia (SKCA) [MIM:[http://omim.org/entry/603903 603903]]; also known as sickle cell disease. Sickle cell anemia is characterized by abnormally shaped red cells resulting in chronic anemia and periodic episodes of pain, serious infections and damage to vital organs. Normal red blood cells are round and flexible and flow easily through blood vessels, but in sickle cell anemia, the abnormal hemoglobin (called Hb S) causes red blood cells to become stiff. They are C-shaped and resembles a sickle. These stiffer red blood cells can led to microvascular occlusion thus cutting off the blood supply to nearby tissues. Defects in HBB are the cause of beta-thalassemia dominant inclusion body type (B-THALIB) [MIM:[http://omim.org/entry/603902 603902]]. An autosomal dominant form of beta thalassemia characterized by moderate anemia, lifelong jaundice, cholelithiasis and splenomegaly, marked morphologic changes in the red cells, erythroid hyperplasia of the bone marrow with increased numbers of multinucleate red cell precursors, and the presence of large inclusion bodies in the normoblasts, both in the marrow and in the peripheral blood after splenectomy.<ref>PMID:1971109</ref>	+	</td></tr><tr><td class="sblockLbl"><b>[[Ligand\|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene>, <scene name='pdbligand=MNC:METHYL+ISOCYANIDE'>MNC</scene><br>
-		+	<tr><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2hbd FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2hbd OCA], [http://www.rcsb.org/pdb/explore.do?structureId=2hbd RCSB], [http://www.ebi.ac.uk/pdbsum/2hbd PDBsum]</span></td></tr>
-	==Function==	+	<table>
-	[[http://www.uniprot.org/uniprot/HBA_HUMAN HBA_HUMAN]] Involved in oxygen transport from the lung to the various peripheral tissues. [[http://www.uniprot.org/uniprot/HBB_HUMAN HBB_HUMAN]] Involved in oxygen transport from the lung to the various peripheral tissues.<ref>PMID:16904236</ref> LVV-hemorphin-7 potentiates the activity of bradykinin, causing a decrease in blood pressure.<ref>PMID:16904236</ref>	+	== Disease ==
-		+	[[http://www.uniprot.org/uniprot/HBA_HUMAN HBA_HUMAN]] Defects in HBA1 may be a cause of Heinz body anemias (HEIBAN) [MIM:[http://omim.org/entry/140700 140700]]. This is a form of non-spherocytic hemolytic anemia of Dacie type 1. After splenectomy, which has little benefit, basophilic inclusions called Heinz bodies are demonstrable in the erythrocytes. Before splenectomy, diffuse or punctate basophilia may be evident. Most of these cases are probably instances of hemoglobinopathy. The hemoglobin demonstrates heat lability. Heinz bodies are observed also with the Ivemark syndrome (asplenia with cardiovascular anomalies) and with glutathione peroxidase deficiency.<ref>PMID:2833478</ref> Defects in HBA1 are the cause of alpha-thalassemia (A-THAL) [MIM:[http://omim.org/entry/604131 604131]]. The thalassemias are the most common monogenic diseases and occur mostly in Mediterranean and Southeast Asian populations. The hallmark of alpha-thalassemia is an imbalance in globin-chain production in the adult HbA molecule. The level of alpha chain production can range from none to very nearly normal levels. Deletion of both copies of each of the two alpha-globin genes causes alpha(0)-thalassemia, also known as homozygous alpha thalassemia. Due to the complete absence of alpha chains, the predominant fetal hemoglobin is a tetramer of gamma-chains (Bart hemoglobin) that has essentially no oxygen carrying capacity. This causes oxygen starvation in the fetal tissues leading to prenatal lethality or early neonatal death. The loss of three alpha genes results in high levels of a tetramer of four beta chains (hemoglobin H), causing a severe and life-threatening anemia known as hemoglobin H disease. Untreated, most patients die in childhood or early adolescence. The loss of two alpha genes results in mild alpha-thalassemia, also known as heterozygous alpha-thalassemia. Affected individuals have small red cells and a mild anemia (microcytosis). If three of the four alpha-globin genes are functional, individuals are completely asymptomatic. Some rare forms of alpha-thalassemia are due to point mutations (non-deletional alpha-thalassemia). The thalassemic phenotype is due to unstable globin alpha chains that are rapidly catabolized prior to formation of the alpha-beta heterotetramers. Note=Alpha(0)-thalassemia is associated with non-immune hydrops fetalis, a generalized edema of the fetus with fluid accumulation in the body cavities due to non-immune causes. Non-immune hydrops fetalis is not a diagnosis in itself but a symptom, a feature of many genetic disorders, and the end-stage of a wide variety of disorders. Defects in HBA1 are the cause of hemoglobin H disease (HBH) [MIM:[http://omim.org/entry/613978 613978]]. HBH is a form of alpha-thalassemia due to the loss of three alpha genes. This results in high levels of a tetramer of four beta chains (hemoglobin H), causing a severe and life-threatening anemia. Untreated, most patients die in childhood or early adolescence.<ref>PMID:10569720</ref> [[http://www.uniprot.org/uniprot/HBB_HUMAN HBB_HUMAN]] Defects in HBB may be a cause of Heinz body anemias (HEIBAN) [MIM:[http://omim.org/entry/140700 140700]]. This is a form of non-spherocytic hemolytic anemia of Dacie type 1. After splenectomy, which has little benefit, basophilic inclusions called Heinz bodies are demonstrable in the erythrocytes. Before splenectomy, diffuse or punctate basophilia may be evident. Most of these cases are probably instances of hemoglobinopathy. The hemoglobin demonstrates heat lability. Heinz bodies are observed also with the Ivemark syndrome (asplenia with cardiovascular anomalies) and with glutathione peroxidase deficiency.<ref>PMID:186485</ref> <ref>PMID:6259091</ref> <ref>PMID:2599881</ref> <ref>PMID:8704193</ref> Defects in HBB are the cause of beta-thalassemia (B-THAL) [MIM:[http://omim.org/entry/613985 613985]]. A form of thalassemia. Thalassemias are common monogenic diseases occurring mostly in Mediterranean and Southeast Asian populations. The hallmark of beta-thalassemia is an imbalance in globin-chain production in the adult HbA molecule. Absence of beta chain causes beta(0)-thalassemia, while reduced amounts of detectable beta globin causes beta(+)-thalassemia. In the severe forms of beta-thalassemia, the excess alpha globin chains accumulate in the developing erythroid precursors in the marrow. Their deposition leads to a vast increase in erythroid apoptosis that in turn causes ineffective erythropoiesis and severe microcytic hypochromic anemia. Clinically, beta-thalassemia is divided into thalassemia major which is transfusion dependent, thalassemia intermedia (of intermediate severity), and thalassemia minor that is asymptomatic.<ref>PMID:1971109</ref> Defects in HBB are the cause of sickle cell anemia (SKCA) [MIM:[http://omim.org/entry/603903 603903]]; also known as sickle cell disease. Sickle cell anemia is characterized by abnormally shaped red cells resulting in chronic anemia and periodic episodes of pain, serious infections and damage to vital organs. Normal red blood cells are round and flexible and flow easily through blood vessels, but in sickle cell anemia, the abnormal hemoglobin (called Hb S) causes red blood cells to become stiff. They are C-shaped and resembles a sickle. These stiffer red blood cells can led to microvascular occlusion thus cutting off the blood supply to nearby tissues. Defects in HBB are the cause of beta-thalassemia dominant inclusion body type (B-THALIB) [MIM:[http://omim.org/entry/603902 603902]]. An autosomal dominant form of beta thalassemia characterized by moderate anemia, lifelong jaundice, cholelithiasis and splenomegaly, marked morphologic changes in the red cells, erythroid hyperplasia of the bone marrow with increased numbers of multinucleate red cell precursors, and the presence of large inclusion bodies in the normoblasts, both in the marrow and in the peripheral blood after splenectomy.<ref>PMID:1971109</ref>
-	==~~About this Structure~~==	+	== Function ==
-	[[~~2hbd~~]] ~~is a 2 chain~~ structure ~~with sequence from~~ [http://en.~~wikipedia~~.~~org~~/~~wiki/Homo_sapiens Homo sapiens~~]. ~~Full crystallographic information is~~ available from [http://~~oca~~.~~weizmann~~.ac.il/~~oca-bin~~/~~ocashort~~?id=~~2HBD OCA~~].	+	[[http://www.uniprot.org/uniprot/HBA_HUMAN HBA_HUMAN]] Involved in oxygen transport from the lung to the various peripheral tissues. [[http://www.uniprot.org/uniprot/HBB_HUMAN HBB_HUMAN]] Involved in oxygen transport from the lung to the various peripheral tissues.<ref>PMID:16904236</ref> LVV-hemorphin-7 potentiates the activity of bradykinin, causing a decrease in blood pressure.<ref>PMID:16904236</ref>
		+	== Evolutionary Conservation ==
		+	[[Image:Consurf_key_small.gif\|200px\|right]]
		+	Check<jmol>
		+	<jmolCheckbox>
		+	<scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/hb/2hbd_consurf.spt"</scriptWhenChecked>
		+	<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
		+	<text>to colour the structure by Evolutionary Conservation</text>
		+	</jmolCheckbox>
		+	</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary\|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/chain_selection.php?pdb_ID=2ata ConSurf].
		+	<div style="clear:both"></div>

	==See Also==		==See Also==
-	*[[Hemoglobin\|Hemoglobin]]	+	*[[Hemoglobin 3D structures\|Hemoglobin 3D structures]]
-		+	== References ==
-	==~~Reference~~==	+	<references/>
-	<references ~~group="xtra"~~/><~~references~~/>	+	__TOC__
		+	</StructureSection>
	[[Category: Homo sapiens]]		[[Category: Homo sapiens]]
	[[Category: Johnson, K A.]]		[[Category: Johnson, K A.]]

OCA at 02:32, 25 March 2013

2013-03-25T02:32:43Z

←Older revision		Revision as of 02:32, 25 March 2013
Line 1:		Line 1:
-	[[Image:2hbd.png\|left\|200px]]
-
	{{STRUCTURE_2hbd\| PDB=2hbd \| SCENE= }}		{{STRUCTURE_2hbd\| PDB=2hbd \| SCENE= }}
-
	===HIGH RESOLUTION X-RAY STRUCTURES OF MYOGLOBIN-AND HEMOGLOBIN-ALKYL ISOCYANIDE COMPLEXES===		===HIGH RESOLUTION X-RAY STRUCTURES OF MYOGLOBIN-AND HEMOGLOBIN-ALKYL ISOCYANIDE COMPLEXES===

		+	==Disease==
		+	[[http://www.uniprot.org/uniprot/HBA_HUMAN HBA_HUMAN]] Defects in HBA1 may be a cause of Heinz body anemias (HEIBAN) [MIM:[http://omim.org/entry/140700 140700]]. This is a form of non-spherocytic hemolytic anemia of Dacie type 1. After splenectomy, which has little benefit, basophilic inclusions called Heinz bodies are demonstrable in the erythrocytes. Before splenectomy, diffuse or punctate basophilia may be evident. Most of these cases are probably instances of hemoglobinopathy. The hemoglobin demonstrates heat lability. Heinz bodies are observed also with the Ivemark syndrome (asplenia with cardiovascular anomalies) and with glutathione peroxidase deficiency.<ref>PMID:2833478</ref> Defects in HBA1 are the cause of alpha-thalassemia (A-THAL) [MIM:[http://omim.org/entry/604131 604131]]. The thalassemias are the most common monogenic diseases and occur mostly in Mediterranean and Southeast Asian populations. The hallmark of alpha-thalassemia is an imbalance in globin-chain production in the adult HbA molecule. The level of alpha chain production can range from none to very nearly normal levels. Deletion of both copies of each of the two alpha-globin genes causes alpha(0)-thalassemia, also known as homozygous alpha thalassemia. Due to the complete absence of alpha chains, the predominant fetal hemoglobin is a tetramer of gamma-chains (Bart hemoglobin) that has essentially no oxygen carrying capacity. This causes oxygen starvation in the fetal tissues leading to prenatal lethality or early neonatal death. The loss of three alpha genes results in high levels of a tetramer of four beta chains (hemoglobin H), causing a severe and life-threatening anemia known as hemoglobin H disease. Untreated, most patients die in childhood or early adolescence. The loss of two alpha genes results in mild alpha-thalassemia, also known as heterozygous alpha-thalassemia. Affected individuals have small red cells and a mild anemia (microcytosis). If three of the four alpha-globin genes are functional, individuals are completely asymptomatic. Some rare forms of alpha-thalassemia are due to point mutations (non-deletional alpha-thalassemia). The thalassemic phenotype is due to unstable globin alpha chains that are rapidly catabolized prior to formation of the alpha-beta heterotetramers. Note=Alpha(0)-thalassemia is associated with non-immune hydrops fetalis, a generalized edema of the fetus with fluid accumulation in the body cavities due to non-immune causes. Non-immune hydrops fetalis is not a diagnosis in itself but a symptom, a feature of many genetic disorders, and the end-stage of a wide variety of disorders. Defects in HBA1 are the cause of hemoglobin H disease (HBH) [MIM:[http://omim.org/entry/613978 613978]]. HBH is a form of alpha-thalassemia due to the loss of three alpha genes. This results in high levels of a tetramer of four beta chains (hemoglobin H), causing a severe and life-threatening anemia. Untreated, most patients die in childhood or early adolescence.<ref>PMID:10569720</ref> [[http://www.uniprot.org/uniprot/HBB_HUMAN HBB_HUMAN]] Defects in HBB may be a cause of Heinz body anemias (HEIBAN) [MIM:[http://omim.org/entry/140700 140700]]. This is a form of non-spherocytic hemolytic anemia of Dacie type 1. After splenectomy, which has little benefit, basophilic inclusions called Heinz bodies are demonstrable in the erythrocytes. Before splenectomy, diffuse or punctate basophilia may be evident. Most of these cases are probably instances of hemoglobinopathy. The hemoglobin demonstrates heat lability. Heinz bodies are observed also with the Ivemark syndrome (asplenia with cardiovascular anomalies) and with glutathione peroxidase deficiency.<ref>PMID:186485</ref><ref>PMID:6259091</ref><ref>PMID:2599881</ref><ref>PMID:8704193</ref> Defects in HBB are the cause of beta-thalassemia (B-THAL) [MIM:[http://omim.org/entry/613985 613985]]. A form of thalassemia. Thalassemias are common monogenic diseases occurring mostly in Mediterranean and Southeast Asian populations. The hallmark of beta-thalassemia is an imbalance in globin-chain production in the adult HbA molecule. Absence of beta chain causes beta(0)-thalassemia, while reduced amounts of detectable beta globin causes beta(+)-thalassemia. In the severe forms of beta-thalassemia, the excess alpha globin chains accumulate in the developing erythroid precursors in the marrow. Their deposition leads to a vast increase in erythroid apoptosis that in turn causes ineffective erythropoiesis and severe microcytic hypochromic anemia. Clinically, beta-thalassemia is divided into thalassemia major which is transfusion dependent, thalassemia intermedia (of intermediate severity), and thalassemia minor that is asymptomatic.<ref>PMID:1971109</ref> Defects in HBB are the cause of sickle cell anemia (SKCA) [MIM:[http://omim.org/entry/603903 603903]]; also known as sickle cell disease. Sickle cell anemia is characterized by abnormally shaped red cells resulting in chronic anemia and periodic episodes of pain, serious infections and damage to vital organs. Normal red blood cells are round and flexible and flow easily through blood vessels, but in sickle cell anemia, the abnormal hemoglobin (called Hb S) causes red blood cells to become stiff. They are C-shaped and resembles a sickle. These stiffer red blood cells can led to microvascular occlusion thus cutting off the blood supply to nearby tissues. Defects in HBB are the cause of beta-thalassemia dominant inclusion body type (B-THALIB) [MIM:[http://omim.org/entry/603902 603902]]. An autosomal dominant form of beta thalassemia characterized by moderate anemia, lifelong jaundice, cholelithiasis and splenomegaly, marked morphologic changes in the red cells, erythroid hyperplasia of the bone marrow with increased numbers of multinucleate red cell precursors, and the presence of large inclusion bodies in the normoblasts, both in the marrow and in the peripheral blood after splenectomy.<ref>PMID:1971109</ref>
		+
		+	==Function==
		+	[[http://www.uniprot.org/uniprot/HBA_HUMAN HBA_HUMAN]] Involved in oxygen transport from the lung to the various peripheral tissues. [[http://www.uniprot.org/uniprot/HBB_HUMAN HBB_HUMAN]] Involved in oxygen transport from the lung to the various peripheral tissues.<ref>PMID:16904236</ref> LVV-hemorphin-7 potentiates the activity of bradykinin, causing a decrease in blood pressure.<ref>PMID:16904236</ref>

	==About this Structure==		==About this Structure==
Line 11:		Line 13:
	==See Also==		==See Also==
	*[[Hemoglobin\|Hemoglobin]]		*[[Hemoglobin\|Hemoglobin]]
		+
		+	==Reference==
		+	<references group="xtra"/><references/>
	[[Category: Homo sapiens]]		[[Category: Homo sapiens]]
	[[Category: Johnson, K A.]]		[[Category: Johnson, K A.]]

OCA at 16:55, 20 October 2012

2012-10-20T16:55:11Z

←Older revision		Revision as of 16:55, 20 October 2012
Line 7:		Line 7:

	==About this Structure==		==About this Structure==
-	[[2hbd]] is a 2 chain structure ~~of [[Hemoglobin]]~~ with sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2HBD OCA].	+	[[2hbd]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2HBD OCA].

	==See Also==		==See Also==