title: Polypeptide activators of cholesterol side-chain cleavage.
abstract: A rate-determining step in the cAMP-dependent action of ACTH on adrenal steroid biosynthesis is the interaction of cholesterol substrate with the cholesterol side-chain cleavage cytochrome P-450 in the mitochondrion. This interaction is rapidly and reversibly sensitive to inhibitors of protein synthesis. For this reason a hormone-dependent, labile protein activator of cholesterol side-chain cleavage has long been postulated as an obligatory intermediate in the tropic regulation of this reaction. Applying recent advances in liquid chromatography, two-dimensional gel electrophoresis, and enzyme reconstitution into liposomes, several laboratories have now reported the isolation and partial characterization of polypeptide candidates for the status of "labile protein."
mesh_terms: D000302:Adrenal Cortex / Q000187:drug effects / Q000378:metabolism; D000324:Adrenocorticotropic Hormone / Q000494:pharmacology; D000818:Animals; D002417:Cattle; D002784:Cholesterol / Q000378:metabolism*; D000242:Cyclic AMP / Q000494:pharmacology; D003513:Cycloheximide / Q000494:pharmacology; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D006168:Guinea Pigs; D008297:Male; D008928:Mitochondria / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000494:pharmacology*; D051381:Rats; D013256:Steroids / Q000096:biosynthesis
chemical_list: D009419:Nerve Tissue Proteins; D013256:Steroids; D000324:Adrenocorticotropic Hormone; D003577:Cytochrome P-450 Enzyme System; D002784:Cholesterol; D003513:Cycloheximide; D000242:Cyclic AMP