Proton transfer in uncoupled variants of cytochrome c oxidase

FEBS Letters

article

Jóhanna Vilhjálmsdóttir¹  Ingrid Albertsson¹  Margareta R. A. Blomberg²  Pia Ädelroth¹  Peter Brzezinski¹ 

[1] Department of Biochemistry and Biophysics, The Arrhenius Laboratories for Natural Sciences, Stockholm University;Department of Organic Chemistry, The Arrhenius Laboratories for Natural Sciences, Stockholm University

关键词: cytochrome aa3;    electron transfer;    mechanism;    membrane protein;    proton pumping;    proton transfer;   

DOI  :  10.1002/1873-3468.13679

来源: John Wiley & Sons Ltd.

【 摘 要 】

Cytochrome c oxidase is a membrane-bound redox-driven proton pump that harbors two proton-transfer pathways, D and K, which are used at different stages of the reaction cycle. Here, we address the question if a D pathway with a modified energy landscape for proton transfer could take over the role of the K pathway when the latter is blocked by a mutation. Our data indicate that structural alterations near the entrance of the D pathway modulate energy barriers that influence proton transfer to the proton-loading site. The data also suggest that during reduction of the catalytic site, its protonation has to occur via the K pathway and that this proton transfer to the catalytic site cannot take place through the D pathway.

【 授权许可】

Unknown