Journal of the American Chemical Society

Isomerization, but not oxidation, is suppressed by a single point mutation, E361Q, in the reaction catalyzed by cholesterol oxidase

NS Sampson, IJ Kass

Index: Sampson, Nicole S.; Kass, Ignatius J. Journal of the American Chemical Society, 1997 , vol. 119, # 5 p. 855 - 862

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Citation Number: 40

Abstract

The putative active site base of cholesterol oxidase from Streptomyces has been removed by site-directed mutagenesis and the mutant enzyme characterized. When glutamate-361 is mutated to a glutamine, the isomerization chemistry catalyzed by cholesterol oxidase is suppressed and the intermediate cholest-5-ene-3-one is isolated. The specific activity for oxidation is 20-fold slower than the wild-type reaction, though the specific activity for ...