| Structural highlights
1qxd is a 4 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
| | Ligands: | , ,
| | Related: | 1qxe |
| Resources: | FirstGlance, OCA, RCSB, PDBsum |
Disease
[HBB_HUMAN] Defects in HBB may be a cause of Heinz body anemias (HEIBAN) [MIM: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.[1] [2] [3] [4] Defects in HBB are the cause of beta-thalassemia (B-THAL) [MIM: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.[5] Defects in HBB are the cause of sickle cell anemia (SKCA) [MIM: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: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.[6]
Function
[HBB_HUMAN] Involved in oxygen transport from the lung to the various peripheral tissues.[7] LVV-hemorphin-7 potentiates the activity of bradykinin, causing a decrease in blood pressure.[8]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
Naturally occurring five-membered heterocyclic aldehydes, including 5-hydroxymethyl-2-furfural, increase the oxygen affinity of hemoglobin (Hb) and strongly inhibit the sickling of homozygous sickle red blood (SS) cells. X-ray studies of Hb complexed with these compounds indicate that they form Schiff base adducts in a symmetrical fashion with the N-terminal alphaVal1 nitrogens of Hb. Interestingly, two cocrystal types were isolated during crystallization experiments with deoxygenated Hb (deoxyHb): one crystal type was composed of the low-affinity or tense (T) state Hb quaternary structure; the other crystal type was composed of high-affinity or relaxed state Hb (with a R2 quaternary structure). The R2 crystal appears to be formed as a result of the aldehydes binding to fully or partially ligated Hb in the deoxyHb solution. Repeated attempts to crystallize the compounds with liganded Hb failed, except on rare occasions when very few R state crystals were obtained. Oxygen equilibrium, high performance liquid chromatography (HPLC), antisickling, and X-ray studies suggest that the examined heterocyclic aldehydes may be acting to prevent polymerization of sickle hemoglobin (HbS) by binding to and stabilizing liganded Hb in the form of R2 and/or various relaxed state Hbs, as well as binding to and destabilizing unliganded T state Hb. The proposed mechanism may provide a general model for the antisickling effects of aldehyde containing small molecules that bind to N-terminal alphaVal1 nitrogens of Hb. The examined compounds also represent a new class of potentially therapeutic agents for treating sickle cell disease (SCD).
Structural basis for the potent antisickling effect of a novel class of five-membered heterocyclic aldehydic compounds.,Safo MK, Abdulmalik O, Danso-Danquah R, Burnett JC, Nokuri S, Joshi GS, Musayev FN, Asakura T, Abraham DJ J Med Chem. 2004 Sep 9;47(19):4665-76. PMID:15341482[9]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Thillet J, Cohen-Solal M, Seligmann M, Rosa J. Functional and physicochemical studies of hemoglobin St. Louis beta 28 (B10) Leu replaced by Gln: a variant with ferric beta heme iron. J Clin Invest. 1976 Nov;58(5):1098-1106. PMID:186485 doi:http://dx.doi.org/10.1172/JCI108561
- ↑ Rahbar S, Feagler RJ, Beutler E. Hemoglobin Hammersmith (beta 42 (CD1) Phe replaced by Ser) associated with severe hemolytic anemia. Hemoglobin. 1981;5(1):97-105. PMID:6259091
- ↑ Blouquit Y, Bardakdjian J, Lena-Russo D, Arous N, Perrimond H, Orsini A, Rosa J, Galacteros F. Hb Bruxelles: alpha 2A beta (2)41 or 42(C7 or CD1)Phe deleted. Hemoglobin. 1989;13(5):465-74. PMID:2599881
- ↑ Rees DC, Rochette J, Schofield C, Green B, Morris M, Parker NE, Sasaki H, Tanaka A, Ohba Y, Clegg JB. A novel silent posttranslational mechanism converts methionine to aspartate in hemoglobin Bristol (beta 67[E11] Val-Met->Asp). Blood. 1996 Jul 1;88(1):341-8. PMID:8704193
- ↑ Thein SL, Hesketh C, Taylor P, Temperley IJ, Hutchinson RM, Old JM, Wood WG, Clegg JB, Weatherall DJ. Molecular basis for dominantly inherited inclusion body beta-thalassemia. Proc Natl Acad Sci U S A. 1990 May;87(10):3924-8. PMID:1971109
- ↑ Thein SL, Hesketh C, Taylor P, Temperley IJ, Hutchinson RM, Old JM, Wood WG, Clegg JB, Weatherall DJ. Molecular basis for dominantly inherited inclusion body beta-thalassemia. Proc Natl Acad Sci U S A. 1990 May;87(10):3924-8. PMID:1971109
- ↑ Ianzer D, Konno K, Xavier CH, Stocklin R, Santos RA, de Camargo AC, Pimenta DC. Hemorphin and hemorphin-like peptides isolated from dog pancreas and sheep brain are able to potentiate bradykinin activity in vivo. Peptides. 2006 Nov;27(11):2957-66. Epub 2006 Aug 9. PMID:16904236 doi:S0196-9781(06)00309-3
- ↑ Ianzer D, Konno K, Xavier CH, Stocklin R, Santos RA, de Camargo AC, Pimenta DC. Hemorphin and hemorphin-like peptides isolated from dog pancreas and sheep brain are able to potentiate bradykinin activity in vivo. Peptides. 2006 Nov;27(11):2957-66. Epub 2006 Aug 9. PMID:16904236 doi:S0196-9781(06)00309-3
- ↑ Safo MK, Abdulmalik O, Danso-Danquah R, Burnett JC, Nokuri S, Joshi GS, Musayev FN, Asakura T, Abraham DJ. Structural basis for the potent antisickling effect of a novel class of five-membered heterocyclic aldehydic compounds. J Med Chem. 2004 Sep 9;47(19):4665-76. PMID:15341482 doi:http://dx.doi.org/10.1021/jm0498001
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