The affinity label (3S)-spiro left bracket 5 alpha -androstane-3,2 prime -oxirane right bracket -17 beta -ol (1 beta ) inhibits 3-oxo- DELTA **5-steroid isomerase with a stoichiometry of one molecule of inhibitor to one enzyme monomer. The trypsin digest of the inhibited enzyme shows two distinct steroid-bound peptides, both of which are derived from residues 14-45 of the enzyme. The two modified peptides (TPS//1 and TPS//2) were isolated by HPLC, and each was shown to have an ester bond linking the steroid to the peptide fragment. Hydrolysis of each of the two peptide-steroid adducts releases a different steroid. TPS//1 gives 3 alpha -(hydroxymethyl)-5 alpha -androstane-3 beta ,17 beta -diol (S//1) whereas TPS//2 releases 3 beta -(hydroxymethyl)-5 alpha -androstane-3 alpha ,17 beta -diol (S//2).
|Original language||English (US)|
|Number of pages||6|
|Journal||Journal of the American Chemical Society|
|State||Published - Jan 1 1984|
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