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Action of bovine serum albumin on cytochrome c oxidase activity and proton pumping: a role for fatty acids in enzyme function?
Author(s) -
Sharpe Martyn,
Perin Ivano,
Nicholls Peter
Publication year - 1996
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(96)00721-1
Subject(s) - cytochrome c oxidase , bovine serum albumin , chemistry , mixed function oxidase , enzyme , biochemistry , albumin , cytochrome c , cytochrome , mitochondrion
Bovine serum albumin (BSA) at micromolar concentrations causes a red shift of the Soret band of bovine cytochrome c oxidase with a slow biphasic time course. It also inhibits the turnover of detergent‐isolated enzyme in a similarly slow manner; the progress of this inhibition is halted by palmitate and other fatty acids. The inhibitory bovine serum albumin effect may involve fatty acid depletion from the enzyme. Respiration by cytochrome c oxidase vesicles (proteoliposomes) in the presence of ionophores (uncontrolled) shows only a small inhibition by BSA but preincubation of such vesicles with BSA induces a loss of proton pumping activity. After incubation of BSA‐depleted proteoliposomes in the presence of reductant with combinations of fatty acids, pumping activity can be fully restored, suggesting a supportive or even essential role of endogenous fatty acids in H + translocation by this membranous enzyme.