title: Respiratory systems and cytochromes in Campylobacter fetus subsp. intestinalis.
abstract: Cell suspensions of Campylobacter fetus subsp. intestinalis grown microaerophilically in complex media consumed oxygen in the presence of formate, succinate, and DL-lactate, and membranes had the corresponding dehydrogenase activities. The cells and membranes also had ascorbate-N,N,N',N'-tetramethyl-p-phenylenediamine oxidase activity which was cyanide sensitive. The fumarate reductase activity in the membranes was inhibited by p-chloromercuriphenylsulfonate, and this enzyme was probably responsible for the succinate dehydrogenase activity. Cytochrome c was predominant in the membranes, and a major proportion of this pigment exhibited a carbon monoxide-binding spectrum. Approximately 60% of the total membrane cytochrome c, measured with dithionite as the reductant, was also reduced by ascorbate-N,N,N',N'-tetramethyl-p-phenylenediamine. A similar proportion of the membrane cytochrome c was reduced by succinate under anaerobic conditions, whereas formate reduced more than 90% of the total cytochrome under these conditions. 2-Heptyl-4-hydroxyquinoline-N-oxide inhibited reduction of cytochrome c with succinate, and the reduced spectrum of cytochrome b became evident. The inhibitor delayed reduction of cytochrome c with formate, but the final level of reduction was unaffected. We conclude that the respiratory chain includes low- and high-potential forms of cytochromes c and b; the carbon monoxide-binding form of cytochrome c might function as a terminal oxidase.
mesh_terms: D002167:Campylobacter / Q000378:metabolism*; D003574:Cytochrome c Group / Q000032:analysis / Q000378:metabolism*; D003580:Cytochromes / Q000032:analysis / Q000378:metabolism*; D005650:Fumarates / Q000378:metabolism; D010101:Oxygen Consumption; D013385:Succinate Dehydrogenase / Q000378:metabolism; D013386:Succinates / Q000378:metabolism
chemical_list: D003574:Cytochrome c Group; D003580:Cytochromes; D005650:Fumarates; D013386:Succinates; D013385:Succinate Dehydrogenase