1COH

STRUCTURE OF HAEMOGLOBIN IN THE DEOXY QUATERNARY STATE WITH LIGAND BOUND AT THE ALPHA HAEMS

1COH の概要

• エントリーDOI: 10.2210/pdb1coh/pdb
• 分子名称: HEMOGLOBIN (FERROUS CARBONMONOXY) (ALPHA CHAIN), HEMOGLOBIN (COBALTOUS DEOXY) (BETA CHAIN), PROTOPORPHYRIN IX CONTAINING FE, ... (6 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: 64609.25

構造登録者

Luisi, B. (登録日: 1989-01-13, 公開日: 1990-01-15, 最終更新日: 2024-05-22)

主引用文献

Luisi, B.,Shibayama, N.
Structure of haemoglobin in the deoxy quaternary state with ligand bound at the alpha haems.
J.Mol.Biol., 206:723-736, 1989

PubMed Abstract: We report the X-ray crystal structure of two analogues of human haemoglobin in the deoxy quaternary (T) state with ligand bound exclusively at the alpha haems. These models were prepared from symmetric, mixed-metal hybrid haemoglobin molecules. The structures of alpha Fe(II) beta Co(II), its carbonmonoxy derivative alpha Fe(II)CO beta Co(II), and alpha Fe(II)O2 beta Ni(II) are compared with native deoxy haemoglobin by difference Fourier syntheses at 2.8, 2.9 and 3.5 A resolution, respectively, and the refined alpha Fe(II)CO beta Co(II) structure is analysed. In both the native deoxy and liganded T molecules, the mean plane of the alpha-subunit haem is parallel with the axis of the F helix, but this plane is tilted with respect to the helix axis in the oxy-quaternary R state. The side-chains of LeuFG3 and ValFG5 sterically restrict haem tilting in the T state. We propose that strain energy develops at the contact between the haem and these residues in the liganded T-state haemoglobin, and that the strain is, in part, responsible for the low affinity of the T-state alpha haem.

PubMed: 2738915
DOI: 10.1016/0022-2836(89)90579-2

実験手法

X-RAY DIFFRACTION (2.9 Å)