Tissue-specific regulation of cytochrome c oxidase efficiency by nucleotides.
Cytochrome c oxidase from bovine heart and liver was reconstituted in liposomes in the absence or presence of nucleotides. Intraliposomal ADP, and to a smaller extent intraliposomal ATP, increased the respiratory activity of the heart but not of the liver isozyme under uncoupled but not under coupled conditions, leading to increased respiratory control ratios. In a preceding publication [Anthony, G., Reimann, A., & Kadenbach, B. (1992) Proc. Natl. Acad. Sci. U.S.A. 90, 1652-1656], the stimulatory effect of intraliposomal ADP could be related to interaction with the matrix domain of subunit VIa-h (heart type). The data suggest a regulatory effect of matrix nucleotides in heart and skeletal muscle mitochondria on the efficiency of energy transduction in COX.
Rohdich
F
F
Fachbereich Chemie, Philipps-Universität, Marburg, FRG.
Kadenbach
B
B
D000244:Adenosine Diphosphate / Q000494:pharmacology*; D000255:Adenosine Triphosphate / Q000494:pharmacology*; D000818:Animals; D002417:Cattle; D003576:Electron Transport Complex IV / Q000302:isolation & purification / Q000378:metabolism*; D007700:Kinetics; D008081:Liposomes; D046911:Macromolecular Substances; D008929:Mitochondria, Heart / Q000201:enzymology*; D008930:Mitochondria, Liver / Q000201:enzymology*; D009928:Organ Specificity
D008081:Liposomes; D046911:Macromolecular Substances; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D003576:Electron Transport Complex IV