Anions induce conformational changes and influence the activity and photoaffinity-labelling by 8-azido-ATP of isolated cytochrome c oxidase.
The biphasic effect of anions on the activity of isolated bovine heart cytochrome c oxidase is paralleled by changes in the visible oxidized spectra, indicating the different conformational changes in the enzyme induced by bromide, chloride, sulphate, phosphate, ADP and ATP. Photoaffinity-labelling of most subunits of the isolated enzyme by low concentrations of 8-azido-[gamma-32P]ATP is strongly increased by ATP, ADP and unlabelled 8-azido-ATP in an unspecific manner. With the reconstituted enzyme less subunits are labelled and this labelling is only little affected by nucleotides. The data suggest a highly dynamic structure for isolated bovine heart cytochrome c oxidase.
Reimann
A
A
Fachbereich Chemie, Biochemie, Philipps-Universität, Marburg, Federal Republic of Germany.
Hüther
F J
FJ
Berden
J A
JA
Kadenbach
B
B
D000255:Adenosine Triphosphate / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D000838:Anions / Q000494:pharmacology*; D001386:Azides; D002417:Cattle; D003576:Electron Transport Complex IV / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D009206:Myocardium / Q000201:enzymology; D010084:Oxidation-Reduction; D011487:Protein Conformation / Q000187:drug effects; D013053:Spectrophotometry
D000838:Anions; D001386:Azides; C017040:8-azidoadenosine 5'-triphosphate; D000255:Adenosine Triphosphate; D003576:Electron Transport Complex IV