Modulation of the kinetics of cholesterol side-chain cleavage by an activator and by an inhibitor isolated from the cytosol of the cortex of bovine adrenals.
Two modulators of sterol side-chain cleavage activity have been detected in the cytosol from the cortex of bovine adrenals. One is an inhibitor of side-chain cleavage which increases the Km of a purified and reconstituted mitochondrial side-chain cleavage system for both cholesterol and cholesterol sulfate. It also lowers the Vmax of cleavage when cholesterol sulfate is the substrate. The other modulator is a low molecular weight protein which in the reconstituted system increases the Vmax of cleavage for both substrates but does not affect the Km of either. Side-chain cleavage activity was also found in bovine adrenocortical cytosol and this appears to differ from that present in mitochondria.
D000302:Adrenal Cortex / Q000201:enzymology / Q000378:metabolism*; D000818:Animals; D002417:Cattle; D002784:Cholesterol / Q000378:metabolism*; D003600:Cytosol / Q000201:enzymology; D007700:Kinetics; D008928:Mitochondria / Q000201:enzymology
D002784:Cholesterol