1J40

Direct observation of photolysis-induced tertiary structural changes in human haemoglobin; Crystal structure of alpha(Ni)-beta(Fe-CO) hemoglobin (laser unphotolysed)

1J40 の概要

• エントリーDOI: 10.2210/pdb1j40/pdb
• 関連するPDBエントリー: 1J3Y 1J3Z 1J41
• 分子名称: Hemoglobin alpha Chain, Hemoglobin beta Chain, PROTOPORPHYRIN IX CONTAINING NI(II), ... (7 entities in total)
• 機能のキーワード: tertiary structure changes, crystal photolysis, riken structural genomics/proteomics initiative, rsgi, structural genomics, oxygen storage-transport complex, oxygen storage/transport
• 由来する生物種: Homo sapiens (human); 詳細
• タンパク質・核酸の鎖数: 8
• 化学式量合計: 129385.68

構造登録者

Adachi, S.,Park, S.-Y.,Tame, J.R.H.,Shiro, Y.,Shibayama, N.,RIKEN Structural Genomics/Proteomics Initiative (RSGI) (登録日: 2003-02-21, 公開日: 2003-07-22, 最終更新日: 2024-10-09)

主引用文献

Adachi, S.,Park, S.-Y.,Tame, J.R.H.,Shiro, Y.,Shibayama, N.
Direct observation of photolysis-induced tertiary structural changes in hemoglobin
Proc.Natl.Acad.Sci.USA, 100:7039-7044, 2003

PubMed Abstract: Human Hb, an alpha2beta2 tetrameric oxygen transport protein that switches from a T (tense) to an R (relaxed) quaternary structure during oxygenation, has long served as a model for studying protein allostery in general. Time-resolved spectroscopic measurements after photodissociation of CO-liganded Hb have played a central role in exploring both protein dynamical responses and molecular cooperativity, but the direct visualization and the structural consequences of photodeligation have not yet been reported. Here we present an x-ray study of structural changes induced by photodissociation of half-liganded T-state and fully liganded R-state human Hb at cryogenic temperatures (25-35 K). On photodissociation of CO, structural changes involving the heme and the F-helix are more marked in the alpha subunit than in the beta subunit, and more subtle in the R state than in the T state. Photodeligation causes a significant sliding motion of the T-state beta heme. Our results establish that the structural basis of the low affinity of the T state is radically different between the subunits, because of differences in the packing and chemical tension at the hemes.

PubMed: 12773618
DOI: 10.1073/pnas.1230629100

実験手法

X-RAY DIFFRACTION (1.45 Å)