Flavocytochrome c of Chromatium vinosum. Some enzymatic properties and subunit structure.
The function and the structural features of Chromatium vinosum cytochrome c-552 have been investigated. Cytochrome c-552 has a sulfide-cytochrome c reductase activity and also catalyzes the reduction of elementary sulfur to sulfide with reduced benzylviologen as the electron donor. In the sulfide-cytochrome reduction, horse and yeast cytochromes c act as good electron acceptors, but cytochrome c' or cytochrome c-553(550) purified from the organism does not. The subunit structure of cytochrome c-552 has been studied. The cytochrome is split by 6 M urea into cytochrome and flavoprotein moieties with molecular weights of 21,000 and 46,000, respectively. The flavoprotein moiety is obtained by isoelectric focusing in the presence of 6 M urea and 0.1% beta-mercaptoethanol, while the hemoprotein moiety is obtained by gel filtration with Sephacryl S-200 in the presence of 6 M urea and 0.1 M KCl. Neither subunit has sulfide-cytochrome c reductase activity. Attempts to reconstitute the original flavocytochrome c from the subunits have been unsuccessful.
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002844:Chromatium / Q000378:metabolism*; D003486:Cyanides / Q000494:pharmacology; D003574:Cytochrome c Group / Q000378:metabolism; D006736:Horses; D007700:Kinetics; D046911:Macromolecular Substances; D008970:Molecular Weight; D013045:Species Specificity; D013053:Spectrophotometry
D000596:Amino Acids; D003486:Cyanides; D003574:Cytochrome c Group; D046911:Macromolecular Substances