Structure of the cytochrome c oxidase complex of rat liver. 1. Studies on nearest-neighbour relationship of polypeptides with cross-linking reagents.
Isolated rat liver cytochrome c oxidase was cross-linked with the cleavable reagents dimethyl-3,3'-dithiobispropionimidate (DTBP), 3,3'-dithiobis(succinimidyl)propionate (DSP) and cupric di(1,10-phenanthroline) (CuP). The cross-linked products were separated by high-resolving two-dimensional dodecyl sulfate gel electrophoresis, which separates all thirteen polypeptides of the mammalian enzyme. With cupric di(1,10-phenanthroline) seven polypeptides (I-III, Va, Vb, VIIb and VIII) were cross-linked with each other and with itself, indicating the occurrence of free -SH groups in these polypeptides and a rearrangement of the native structure of the complex by cupric di(1,10-phenanthroline). With dimethyl-3,3'-dithiobispropionimidate or 3,3'-dithiobis(succinimidyl)propionate all nuclear-coded polypeptides, with the exception of polypeptide VIIa, formed cross-linked products with the three 'catalytic' polypeptides I-III, which are coded on mitochondrial DNA. Five additional cross-linked pairs were found between nuclear coded polypeptides. The close arrangement of nuclear coded polypeptides with the catalytic polypeptides suggests a regulatory function of these polypeptides.
Jarausch
J
J
Kadenbach
B
B
D000818:Animals; D055598:Chemical Phenomena; D002621:Chemistry; D003432:Cross-Linking Reagents; D003576:Electron Transport Complex IV / Q000302:isolation & purification*; D004591:Electrophoresis, Polyacrylamide Gel; D007096:Imidoesters; D008930:Mitochondria, Liver / Q000201:enzymology*; D010446:Peptide Fragments / Q000032:analysis; D010618:Phenanthrolines; D051381:Rats; D013388:Succinimides
D003432:Cross-Linking Reagents; D007096:Imidoesters; D010446:Peptide Fragments; D010618:Phenanthrolines; D013388:Succinimides; C014741:bis(1,10-phenanthroline)copper(2+) ion; C007471:dimethyl dithiobispropionimidate; D003576:Electron Transport Complex IV; C011240:dithiobis(succinimidylpropionate)