1YOI

COBALT MYOGLOBIN (OXY)

1YOI の概要

• エントリーDOI: 10.2210/pdb1yoi/pdb
• 分子名称: MYOGLOBIN, SULFATE ION, PROTOPORPHYRIN IX CONTAINING CO, ... (5 entities in total)
• 機能のキーワード: heme, oxygen transport, respiratory protein, muscle
• 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: 17982.59

構造登録者

Brucker, E.A.,Phillips Jr., G.N. (登録日: 1996-06-14, 公開日: 1996-12-07, 最終更新日: 2024-02-14)

主引用文献

Brucker, E.A.,Olson, J.S.,Phillips Jr., G.N.,Dou, Y.,Ikeda-Saito, M.
High resolution crystal structures of the deoxy, oxy, and aquomet forms of cobalt myoglobin.
J.Biol.Chem., 271:25419-25422, 1996

PubMed Abstract: The structures of the deoxy, oxy, and aquomet forms of native sperm whale myoglobin reconstituted with cobalt protoporphyrin IX have been determined by x-ray crystallography. As expected, cobalt myoglobin closely resembles native iron myoglobin in overall structure, especially in their respective aquomet forms. In the cobalt oxymyoglobin structure, the Nepsilon of distal histidine 64 lies within hydrogen bonding distance to both the oxygen atom directly bonded to the cobalt and the terminal oxygen atom, in agreement with previous EPR and resonance Raman studies. The metal atom in cobaltous myoglobin does show a small 0.06-A out-of-porphyrin plane displacement when moving from the oxy to deoxy state. In the case of the native iron-containing myoglobin, the oxy to deoxy transition results in a larger 0.16-A displacement of the metal farther out of the porphyrin plane, attributed to an increase in spin from S = 0 to S = 2. The small displacement in cobalt myoglobin is due to a change in coordination geometry, not spin state (S = 1/2 for both cobalt deoxy- and oxymyoglobin). The small out-of-porphyrin plane movement of cobalt which accompanies deoxygenation of myoglobin also occurs in cobalt hemoglobin and serves to explain why cooperativity, although reduced, is still preserved when iron is replaced by cobalt in human hemoglobin.

PubMed: 8810310
DOI: 10.1074/jbc.271.41.25419

実験手法

X-RAY DIFFRACTION (1.65 Å)