2O5O

Manganese horse heart myoglobin, nitrite modified

2O5O の概要

• エントリーDOI: 10.2210/pdb2o5o/pdb
• 関連するPDBエントリー: 1MMB 2O58 2O5B 2O5L 2O5M 2O5Q 2O5S 2O5T
• 分子名称: Myoglobin, SULFATE ION, NITRITE ION, ... (5 entities in total)
• 機能のキーワード: manganese myoglobin, manganese protoporphyrin ix, nitrite, horse heart, oxygen storage-transport complex, oxygen storage/transport
• 由来する生物種: Equus caballus (horse)
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 17837.23

構造登録者

Richter-Addo, G.B.,Zahran, Z.N.,Chooback, L.,Copeland, D.M.,West, A.H. (登録日: 2006-12-06, 公開日: 2007-10-16, 最終更新日: 2023-12-27)

主引用文献

Zahran, Z.N.,Chooback, L.,Copeland, D.M.,West, A.H.,Richter-Addo, G.B.
Crystal structures of manganese- and cobalt-substituted myoglobin in complex with NO and nitrite reveal unusual ligand conformations.
J.Inorg.Biochem., 102:216-233, 2008

PubMed Abstract: Nitrite is now recognized as a storage pool of bioactive nitric oxide (NO). Hemoglobin (Hb) and myoglobin (Mb) convert, under certain conditions, nitrite to NO. This newly discovered nitrite reductase activity of Hb and Mb provides an attractive alternative to mammalian NO synthesis from the NO synthase pathway that requires dioxygen. We recently reported the X-ray crystal structure of the nitrite adduct of ferric horse heart Mb, and showed that the nitrite ligand binds in an unprecedented O-binding (nitrito) mode to the d(5) ferric center in Mb(III)(ONO) [D.M. Copeland, A. Soares, A.H. West, G.B. Richter-Addo, J. Inorg. Biochem. 100 (2006) 1413-1425]. We also showed that the distal pocket in Mb allows for different conformations of the NO ligand (120 degrees and 144 degrees ) in Mb(II)NO depending on the mode of preparation of the compound. In this article, we report the crystal structures of the nitrite and NO adducts of manganese-substituted hh Mb (a d(4) system) and of the nitrite adduct of cobalt-substituted hh Mb (a d(6) system). We show that the distal His64 residue directs the nitrite ligand towards the rare nitrito O-binding mode in Mn(III)Mb and Co(III)Mb. We also report that the distal pocket residues allow a stabilization of an unprecendented bent MnNO moiety in Mn(II)MbNO. These crystal structural data, when combined with the data for the aquo, methanol, and azide MnMb derivatives, provide information on the role of distal pocket residues in the observed binding modes of nitrite and NO ligands to wild-type and metal-substituted Mb.

PubMed: 17905436
DOI: 10.1016/j.jinorgbio.2007.08.002

実験手法

X-RAY DIFFRACTION (1.6 Å)