Numazawa M, Satoh S, Ogura Y, Nagaoka M. Determination of estradiol 2- and 16 alpha-hydroxylase activities in rat liver microsomes using high-performance liquid chromatography.
Anal Biochem 1985;
149:409-14. [PMID:
4073497 DOI:
10.1016/0003-2697(85)90591-3]
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Abstract
We have developed a sensitive and nonradiometric assay of estradiol 2- and 16 alpha-hydroxylase activities using reverse-phase high-performance liquid chromatography with voltametric detector. The 2- and 16 alpha-hydroxylated estrogens produced by the incubation of estradiol with rat liver microsomes were initially separated into the catechol and phenolic fractions using a QAE-Sephadex A-25 borate column. The metabolites were detected in quantities as low as 0.5-1 ng using 3-methoxy-1,3,5(10)-estratriene-2,16 alpha,17 beta-triol or 4-hydroxyestrone 17-oxime as an internal standard. Apparent Km and Vmax of the 2- and 16 alpha-hydroxylases were 41.9 microM and 1.3 nmol/mg protein/min, and 82 microM and 480 pmol/mg protein/min, respectively.
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