The role of the sugar regions of components of the cytochrome P-450-linked mixed-function oxidase (monooxygenase) system of bovine adrenocortical mitochondria.

Cytochrome P-450scc from bovine adrenocortical mitochondria was found to be a glycoprotein, similar to NADPH-adrenodoxin reductase. The role of sugar moieties of components of the cytochrome P-450-linked mixed-function oxidase system was investigated. The NADPH-ferricyanide reductase activity of NADPH-adrenodoxin reductase was not affected by neuraminidase treatment, but NADPH-cytochrome c reductase activity of NADPH-adrenodoxin reductase and adrenodoxin was lost. Cytochrome P-450scc treated with neuraminidase could not be reduced by NADPH-adrenodoxin reductase and adrenodoxin, and the side-chain cleavage activity of cholesterol by the cytochrome P-450-linked mixed-function oxidase system was lost by neuraminidase treatment of cytochrome P-450scc or NADPH-adrenodoxin reductase or both. These results indicate that the sugar moieties of the components of the cytochrome P-450-linked mixed-function oxidase system are necessary for binding and attaching of the components and electron transport.