1rps
From Proteopedia
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|PDB= 1rps |SIZE=350|CAPTION= <scene name='initialview01'>1rps</scene>, resolution 2.11Å | |PDB= 1rps |SIZE=350|CAPTION= <scene name='initialview01'>1rps</scene>, resolution 2.11Å | ||
|SITE= | |SITE= | ||
| - | |LIGAND= <scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene> | + | |LIGAND= <scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene>, <scene name='pdbligand=NO:NITROGEN+OXIDE'>NO</scene> |
|ACTIVITY= | |ACTIVITY= | ||
|GENE= | |GENE= | ||
| + | |DOMAIN= | ||
| + | |RELATEDENTRY=[[1rq3|1RQ3]], [[1rq4|1RQ4]], [[1rqa|1RQA]] | ||
| + | |RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1rps FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1rps OCA], [http://www.ebi.ac.uk/pdbsum/1rps PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1rps RCSB]</span> | ||
}} | }} | ||
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==Overview== | ==Overview== | ||
In addition to interacting with hemoglobin as a heme ligand to form nitrosylhemoglobin, NO can react with cysteine sulfhydryl groups to form S-nitrosocysteine or cysteine oxides such as cysteinesulfenic acid. Both modes of interaction are very sensitive to the quaternary structure of hemoglobin. To directly view the interaction of NO with quaternary-T deoxyhemoglobin, crystallographic studies were carried out on crystals of deoxyhemoglobin that were exposed to gaseous NO under a variety of conditions. Consistent with previous spectroscopic studies in solution, these crystallographic studies show that the binding of NO to the heme groups of crystalline wild-type deoxyhemoglobin ruptures the Fe-proximal histidine bonds of the alpha-subunits but not the beta-subunits. This finding supports Perutz's theory that ligand binding induces tension in the alpha Fe-proximal histidine bond. To test Perutz's theory, deoxy crystals of the mutant hemoglobin betaW37E were exposed to NO. This experiment was carried out because previous studies have shown that this mutation greatly reduces the quaternary constraints that oppose the ligand-induced movement of the alpha-heme Fe atom into the plane of the porphyrin ring. As hypothesized, the Fe-proximal histidine bonds in both the beta- and the alpha-subunits remain intact in crystalline betaW37E after exposure to NO. With regard to S-nitrosocysteine or cysteine oxide formation, no evidence for the reaction of NO with any cysteine residues was detected under anaerobic conditions. However, when deoxyhemoglobin crystals are first exposed to air and then to NO, the appearance of additional electron density indicates that Cys93(F9)beta has been modified, most likely to cysteinesulfenic acid. This modification of Cys93(F9)beta disrupts the intrasubunit salt bridge between His146(HC3)beta and Asp94(FG1)beta, a key feature of the quaternary-T hemoglobin structure. Also presented is a reanalysis of our previous crystallographic studies [Chan, N.-L., et al. (1998) Biochemistry 37, 16459-16464] of the interaction of NO with liganded hemoglobin in the quaternary-R2 structure. These studies showed additional electron density at Cys93(F9)beta that was consistent with an NO adduct. However, for reasons discussed in this paper, we now believe that this adduct may be the Hb-S-N.-O-H radical intermediate and not Hb-S-N=O as previously suggested. | In addition to interacting with hemoglobin as a heme ligand to form nitrosylhemoglobin, NO can react with cysteine sulfhydryl groups to form S-nitrosocysteine or cysteine oxides such as cysteinesulfenic acid. Both modes of interaction are very sensitive to the quaternary structure of hemoglobin. To directly view the interaction of NO with quaternary-T deoxyhemoglobin, crystallographic studies were carried out on crystals of deoxyhemoglobin that were exposed to gaseous NO under a variety of conditions. Consistent with previous spectroscopic studies in solution, these crystallographic studies show that the binding of NO to the heme groups of crystalline wild-type deoxyhemoglobin ruptures the Fe-proximal histidine bonds of the alpha-subunits but not the beta-subunits. This finding supports Perutz's theory that ligand binding induces tension in the alpha Fe-proximal histidine bond. To test Perutz's theory, deoxy crystals of the mutant hemoglobin betaW37E were exposed to NO. This experiment was carried out because previous studies have shown that this mutation greatly reduces the quaternary constraints that oppose the ligand-induced movement of the alpha-heme Fe atom into the plane of the porphyrin ring. As hypothesized, the Fe-proximal histidine bonds in both the beta- and the alpha-subunits remain intact in crystalline betaW37E after exposure to NO. With regard to S-nitrosocysteine or cysteine oxide formation, no evidence for the reaction of NO with any cysteine residues was detected under anaerobic conditions. However, when deoxyhemoglobin crystals are first exposed to air and then to NO, the appearance of additional electron density indicates that Cys93(F9)beta has been modified, most likely to cysteinesulfenic acid. This modification of Cys93(F9)beta disrupts the intrasubunit salt bridge between His146(HC3)beta and Asp94(FG1)beta, a key feature of the quaternary-T hemoglobin structure. Also presented is a reanalysis of our previous crystallographic studies [Chan, N.-L., et al. (1998) Biochemistry 37, 16459-16464] of the interaction of NO with liganded hemoglobin in the quaternary-R2 structure. These studies showed additional electron density at Cys93(F9)beta that was consistent with an NO adduct. However, for reasons discussed in this paper, we now believe that this adduct may be the Hb-S-N.-O-H radical intermediate and not Hb-S-N=O as previously suggested. | ||
| - | |||
| - | ==Disease== | ||
| - | Known diseases associated with this structure: Erythremias, alpha- OMIM:[[http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=141800 141800]], Erythremias, beta- OMIM:[[http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=141900 141900]], Erythrocytosis OMIM:[[http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=141850 141850]], HPFH, deletion type OMIM:[[http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=141900 141900]], Heinz body anemia OMIM:[[http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=141850 141850]], Heinz body anemias, alpha- OMIM:[[http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=141800 141800]], Heinz body anemias, beta- OMIM:[[http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=141900 141900]], Hemoglobin H disease OMIM:[[http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=141850 141850]], Hypochromic microcytic anemia OMIM:[[http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=141850 141850]], Methemoglobinemias, alpha- OMIM:[[http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=141800 141800]], Methemoglobinemias, beta- OMIM:[[http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=141900 141900]], Sickle cell anemia OMIM:[[http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=141900 141900]], Thalassemia, alpha- OMIM:[[http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=141850 141850]], Thalassemia-beta, dominant inclusion-body OMIM:[[http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=141900 141900]], Thalassemias, alpha- OMIM:[[http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=141800 141800]], Thalassemias, beta- OMIM:[[http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=141900 141900]] | ||
==About this Structure== | ==About this Structure== | ||
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[[Category: Kavanaugh, J S.]] | [[Category: Kavanaugh, J S.]] | ||
[[Category: Rogers, P H.]] | [[Category: Rogers, P H.]] | ||
| - | [[Category: HEM]] | ||
| - | [[Category: NO]] | ||
[[Category: globin]] | [[Category: globin]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 23:31:22 2008'' |
Revision as of 20:31, 30 March 2008
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| , resolution 2.11Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | , | ||||||
| Related: | 1RQ3, 1RQ4, 1RQA
| ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Crystallographic Analysis of the Interaction of Nitric Oxide with Quaternary-T Human Hemoglobin. Hemoglobin exposed to NO under anerobic conditions
Overview
In addition to interacting with hemoglobin as a heme ligand to form nitrosylhemoglobin, NO can react with cysteine sulfhydryl groups to form S-nitrosocysteine or cysteine oxides such as cysteinesulfenic acid. Both modes of interaction are very sensitive to the quaternary structure of hemoglobin. To directly view the interaction of NO with quaternary-T deoxyhemoglobin, crystallographic studies were carried out on crystals of deoxyhemoglobin that were exposed to gaseous NO under a variety of conditions. Consistent with previous spectroscopic studies in solution, these crystallographic studies show that the binding of NO to the heme groups of crystalline wild-type deoxyhemoglobin ruptures the Fe-proximal histidine bonds of the alpha-subunits but not the beta-subunits. This finding supports Perutz's theory that ligand binding induces tension in the alpha Fe-proximal histidine bond. To test Perutz's theory, deoxy crystals of the mutant hemoglobin betaW37E were exposed to NO. This experiment was carried out because previous studies have shown that this mutation greatly reduces the quaternary constraints that oppose the ligand-induced movement of the alpha-heme Fe atom into the plane of the porphyrin ring. As hypothesized, the Fe-proximal histidine bonds in both the beta- and the alpha-subunits remain intact in crystalline betaW37E after exposure to NO. With regard to S-nitrosocysteine or cysteine oxide formation, no evidence for the reaction of NO with any cysteine residues was detected under anaerobic conditions. However, when deoxyhemoglobin crystals are first exposed to air and then to NO, the appearance of additional electron density indicates that Cys93(F9)beta has been modified, most likely to cysteinesulfenic acid. This modification of Cys93(F9)beta disrupts the intrasubunit salt bridge between His146(HC3)beta and Asp94(FG1)beta, a key feature of the quaternary-T hemoglobin structure. Also presented is a reanalysis of our previous crystallographic studies [Chan, N.-L., et al. (1998) Biochemistry 37, 16459-16464] of the interaction of NO with liganded hemoglobin in the quaternary-R2 structure. These studies showed additional electron density at Cys93(F9)beta that was consistent with an NO adduct. However, for reasons discussed in this paper, we now believe that this adduct may be the Hb-S-N.-O-H radical intermediate and not Hb-S-N=O as previously suggested.
About this Structure
1RPS is a Protein complex structure of sequences from Homo sapiens. Full crystallographic information is available from OCA.
Reference
Crystallographic analysis of the interaction of nitric oxide with quaternary-T human hemoglobin., Chan NL, Kavanaugh JS, Rogers PH, Arnone A, Biochemistry. 2004 Jan 13;43(1):118-32. PMID:14705937
Page seeded by OCA on Sun Mar 30 23:31:22 2008
