A conserved amphipathic ligand binding region influences k-path-dependent activity of cytochrome C oxidase.

ABSTRACT: A conserved, crystallographically defined bile acid binding site was originally identified in the membrane domain of mammalian and bacterial cytochrome c oxidase (CcO). Current studies show other amphipathic molecules including detergents, fatty acids, steroids, and porphyrins bind to this site and affect the already 50% inhibited activity of the E101A mutant of Rhodobacter sphaeroides CcO as well as altering the activity of wild-type and bovine enzymes. Dodecyl maltoside, Triton X100, C12E8, lysophophatidylcholine, and CHOBIMALT detergents further inhibit RsCcO E101A, with lesser inhibition observed in wild-type. The detergent inhibition is overcome in the presence of micromolar concentrations of steroids and porphyrin analogues including deoxycholate, cholesteryl hemisuccinate, bilirubin

SUBMITTER: Hiser C 

PROVIDER: S-EPMC3622084 | biostudies-literature | 2013 Feb

REPOSITORIES: biostudies-literature