1BAB image
Deposition Date 1992-05-06
Release Date 1994-01-31
Last Version Date 2024-11-13
Entry Detail
PDB ID:
1BAB
Title:
HEMOGLOBIN THIONVILLE: AN ALPHA-CHAIN VARIANT WITH A SUBSTITUTION OF A GLUTAMATE FOR VALINE AT NA-1 AND HAVING AN ACETYLATED METHIONINE NH2 TERMINUS
Biological Source:
Source Organism:
Homo sapiens (Taxon ID: 9606)
Method Details:
Experimental Method:
Resolution:
1.50 Å
R-Value Observed:
0.15
Space Group:
P 1 21 1
Macromolecular Entities
Polymer Type:polypeptide(L)
Molecule:HEMOGLOBIN THIONVILLE (DEOXY) (ALPHA CHAIN)
Gene (Uniprot):HBA1, HBA2
Chain IDs:A, C
Chain Length:143
Number of Molecules:2
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:HEMOGLOBIN THIONVILLE (DEOXY) (BETA CHAIN)
Gene (Uniprot):HBB
Chain IDs:B, D
Chain Length:146
Number of Molecules:2
Biological Source:Homo sapiens
Primary Citation
Hemoglobin Thionville. An alpha-chain variant with a substitution of a glutamate for valine at NA-1 and having an acetylated methionine NH2 terminus.
J.Biol.Chem. 267 12682 12691 (1992)
PMID: 1618774

Abstact

In hemoglobin (Hb) Thionville, the substitution of a glutamic acid for the alpha-chain NH2-terminal valine inhibits the cleavage of the initiator methionine which is then acetylated. The elongation of the alpha-chain NH2 terminus modifies the three-dimensional structure of hemoglobin at a region that is known to have an important role in the allosteric regulation of oxygen binding. Relative to Hb A, Hb Thionville has a lower affinity for oxygen, and the heterotropic allosteric effects of protons, chloride, and bezafibrate are reduced. In contrast, the response to 2,3-diphosphoglycerate is normal. Analysis of oxygen equilibrium data within the framework of the two-state allosteric model indicates that the structure of deoxy Hb Thionville is stabilized relative to that of deoxy Hb A. The x-ray crystal structure of deoxy Hb Thionville shows that the glutamate side chain extends away from the alpha 1-alpha 2 interface, whereas the methionine side chain (which has two conformations) extends into the alpha 1-alpha 2 interface, physically displacing chloride and bezafibrate. The increased stability of deoxy Hb Thionville is due to new intrasubunit and intersubunit contacts made by the methionine. These interactions replace the indirect contacts, made through bound chloride ions, that Val-1 alpha normally contributes to the alpha 1-alpha 2 interface.

Legend

Protein

Chemical

Disease

Primary Citation of related structures