1GZX

Oxy T State Haemoglobin - Oxygen bound at all four haems

1GZX の概要

• エントリーDOI: 10.2210/pdb1gzx/pdb
• 関連するPDBエントリー: 1A00 1A01 1A0U 1A0V 1A0W 1A0X 1A0Y 1A0Z 1A3N 1A3O 1ABW 1ABY 1AJ9 1AXF 1B86 1BAB 1BBB 1BIJ 1BUW 1BZ0 1BZ1 1BZZ 1C7B 1C7C 1C7D 1CBL 1CBM 1CLS 1CMY 1COH 1DKE 1DSH 1DXT 1DXU 1DXV 1G9V 1GBU 1GBV 1GLI 1HAB 1HAC 1HBA 1HBB 1HBS 1HCO 1HDB 1HGA 1HGB 1HGC 1HHO 1IRD 1J7S 1J7W 1J7Y 1JY7 1K0Y 1LJW 1NIH 1QI8 1QSH 1QSI 1RVW 1SDK 1SDL 1THB 1VWT 2HBC 2HBD 2HBE 2HBF 2HBS 2HCO 2HHD 2HHE 4HHB 6HBW
• 分子名称: Hemoglobin subunit alpha, Hemoglobin subunit beta, PROTOPORPHYRIN IX CONTAINING FE, ... (5 entities in total)
• 機能のキーワード: oxygen transport, haem protein, oxygen binding, transport, cooperativity
• 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: 64675.05

構造登録者

Paoli, M.,Liddington, R.,Tame, J.,Wilkinson, A.,Dodson, G. (登録日: 2002-06-07, 公開日: 2002-07-08, 最終更新日: 2024-02-07)

主引用文献

Paoli, M.,Liddington, R.,Tame, J.,Wilkinson, A.,Dodson, G.
Crystal Structure of T State Haemoglobin with Oxygen Bound at All Four Haems.
J.Mol.Biol., 256:775-, 1996

PubMed Abstract: The cooperative binding of oxygen by haemoglobin results from restraints on ligand binding in the T state. The unfavourable interactions made by the ligands at the haems destabilise the T state and favour the high affinity R state. The T <==> R equilibrium leads, in the presence of a ligand, to a rapid increase in the R state population and therefore generates cooperative binding. There is now considerable understanding of this phenomenon, but the interactions that reduce ligand affinity in the T state have not yet been fully explored, owing to the difficulties in preparing T state haemoglobin crystals in which all the subunits are oxygenated. A protocol has been developed to oxygenate deoxy T state adult human haemoglobin (HbA) crystals in air at 4 C at all four haems without significant loss of crystalline order. The X-ray crystal structure, determined to 2.1 A spacing, shows significant changes in the alpha and beta haem pockets as well as changes at the alpha(1)beta(2) interface in the direction of the R quaternary structure. Most of the shifts and deviations from deoxy T state HbA are similar to, but larger than, those previously observed in the T state met and other partially liganded T state forms. They provide clear evidence of haem-haem interaction in the T state.

PubMed: 8642597
DOI: 10.1006/JMBI.1996.0124

実験手法

X-RAY DIFFRACTION (2.1 Å)