Abstract
Using yeast microsomes, 23-hydroxysterols were tested as intermediates in the formation of the sterol side delta 22-double bond. No evidence could be found supporting a two-stage mechanism of desaturation via hydroxylation and dehydration. Sterols with various side chains were tested as substrates. Those with alkyl substituents in the 24-alpha position were poor substrates. A series of sterols, including cyclopropyl sterols, were tested as mechanism-based inhibitors without success. Inhibition was observed with an isocyano-sterol.
Publication types
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Cytochrome P-450 Enzyme System / isolation & purification
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Cytochrome P-450 Enzyme System / metabolism*
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Isotope Labeling / methods
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Microsomes / enzymology
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Molecular Structure
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Oxidoreductases / isolation & purification
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Oxidoreductases / metabolism*
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Saccharomyces cerevisiae / enzymology*
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Saccharomyces cerevisiae Proteins
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Sterols / chemical synthesis
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Sterols / metabolism
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Sterols / pharmacology*
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Substrate Specificity
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Tritium
Substances
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Saccharomyces cerevisiae Proteins
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Sterols
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Tritium
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Cytochrome P-450 Enzyme System
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Oxidoreductases
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ERG5 protein, S cerevisiae