1BAB

HEMOGLOBIN THIONVILLE: AN ALPHA-CHAIN VARIANT WITH A SUBSTITUTION OF A GLUTAMATE FOR VALINE AT NA-1 AND HAVING AN ACETYLATED METHIONINE NH2 TERMINUS

1BAB の概要

• エントリーDOI: 10.2210/pdb1bab/pdb
• 分子名称: HEMOGLOBIN THIONVILLE (DEOXY) (ALPHA CHAIN), HEMOGLOBIN THIONVILLE (DEOXY) (BETA CHAIN), PROTOPORPHYRIN IX CONTAINING FE, ... (5 entities in total)
• 機能のキーワード: oxygen transport
• 由来する生物種: Homo sapiens (human); 詳細
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 65113.61

構造登録者

Kavanaugh, J.S.,Arnone, A. (登録日: 1992-05-06, 公開日: 1994-01-31, 最終更新日: 2024-11-13)

主引用文献

Vasseur, C.,Blouquit, Y.,Kister, J.,Prome, D.,Kavanaugh, J.S.,Rogers, P.H.,Guillemin, C.,Arnone, A.,Galacteros, F.,Poyart, C.,Rosa, J.,Wajcman, H.
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

PubMed Abstract: 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.

PubMed: 1618774

実験手法

X-RAY DIFFRACTION (1.5 Å)