Cholesterol Oxidase microbial

Cholesterol oxidase is used to determine serum cholesterol. The enzyme also finds application in the microanalysis of steroids in food samples and in distinguishing 3-ketosteroids from 3b-hydroxysteroids. Transgenic plants expressing cholesterol oxidase are being investigated in the fight against the cotton boll weevil. CHOD has also been used as a molecular probe to elucidate cellular membrane structures.

Cholesterol oxidase (CHOD) is a monomeric flavoprotein containing FAD that catalyzes the first step in cholesterol catabolism. This bifunctional enzyme oxidizes cholesterol to cholest-5-en-3-one in an FAD-requiring step. This is subsequently isomerized to cholest-4-en-3-one with the release of H₂O₂. Optimum pH of the enzyme is 7.0. Hg²⁺, Ag⁺, ionic detergents inhibit the enzyme activity.

One unit will convert 1.0 μmol of cholesterol to 4-cholesten-3-one per minute at 37 °C and pH 7.0 in a peroxidase linked system.

Dissolves in cold 50 mM potassium phosphate buffer, pH 7.0. Solution is to be prepared just before use.