1DO7

CARBONMONOXY-MYOGLOBIN (MUTANT L29W) REBINDING STRUCTURE AFTER PHOTOLYSIS AT T< 180K

1DO7 の概要

• エントリーDOI: 10.2210/pdb1do7/pdb
• 関連するPDBエントリー: 1DO1 1DO3 1DO4 1DO7
• 関連するBIRD辞書のPRD_ID: PRD_900006
• 分子名称: MYOGLOBIN, alpha-D-glucopyranose-(1-1)-alpha-D-glucopyranose, SULFATE ION, ... (6 entities in total)
• 機能のキーワード: heme, respiratory protein, photolysed myoglobin, ligand migration, oxygen storage-transport complex, oxygen storage/transport
• 由来する生物種: Physeter catodon (sperm whale)
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 18645.14

構造登録者

Ostermann, A.,Waschipky, R.,Parak, F.G.,Nienhaus, G.U. (登録日: 1999-12-19, 公開日: 2000-01-05, 最終更新日: 2024-10-30)

主引用文献

Ostermann, A.,Waschipky, R.,Parak, F.G.,Nienhaus, G.U.
Ligand binding and conformational motions in myoglobin.
Nature, 404:205-208, 2000

PubMed Abstract: Myoglobin, a small globular haem protein that binds gaseous ligands such as O2, CO and NO reversibly at the haem iron, serves as a model for studying structural and dynamic aspects of protein reactions. Time-resolved spectroscopic measurements after photodissociation of the ligand revealed a complex ligand-binding reaction with multiple kinetic intermediates, resulting from protein relaxation and movements of the ligand within the protein. To observe the structural changes induced by ligand dissociation, we have carried out X-ray crystallographic investigations of carbon monoxy-myoglobin (MbCO mutant L29W) crystals illuminated below and above 180 K, complemented by time-resolved infrared spectroscopy of CO rebinding. Here we show that below 180 K photodissociated ligands migrate to specific sites within an internal cavity--the distal haem pocket--of an essentially immobilized, frozen protein, from where they subsequently rebind by thermally activated barrier crossing. Upon photodissociation above 180 K, ligands escape from the distal pocket, aided by protein fluctuations that transiently open exit channels. We recover most of the ligands in a cavity on the opposite side of the haem group.

PubMed: 10724176
DOI: 10.1038/35004622

実験手法

X-RAY DIFFRACTION (1.85 Å)