Coenzyme B Induced Coordination of Coenzyme M via Its Thiol Group to Ni(I) of F430 in Active Methyl-Coenzyme M Reductase

详细信息    查看全文

• 作者：Cinzia Finazzo ; Jeffrey Harmer ; Carsten Bauer ; Bernhard Jaun ; Evert C. Duin ; Felix Mahlert ; Meike Goenrich ; Rudolf K. Thauer ; Sabine Van Doorslaer ; and Arthur Schweiger
• 刊名：Journal of the American Chemical Society
• 出版年：2003
• 出版时间：April 30, 2003
• 年：2003
• 卷：125
• 期：17
• 页码：4988 - 4989
• 全文大小：67K
• 年卷期：v.125,no.17(April 30, 2003)
• ISSN：1520-5126

文摘

Methyl-coenzyme M reductase (MCR) catalyzes the reaction of methyl-coenzyme M (CH₃-S-CoM) with coenzyme B (HS-CoB) to methane and CoM-S-S-CoB. At the active site, it contains the nickel porphinoid F₄₃₀, which has to be in the Ni(I) oxidation state for the enzyme to be active. How the substrates interact with the active site Ni(I) has remained elusive. We report here that coenzyme M (HS-CoM), which is a reversible competitive inhibitor to methyl-coenzyme M, interacts with its thiol group with the Ni(I) and that for interaction the simultaneous presence of coenzyme B is required. The evidence is based on X-band continuous wave EPR and Q-band hyperfine sublevel correlation spectroscopy of MCR in the red2 state induced with ³³S-labeled coenzyme M and unlabeled coenzyme B.