Open AccessEcdysone Oxidase: Reaction and Specificity
Author(s) -
KOOLMAN Jan,
KARLSON Peter
Publication year - 1978
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1978.tb12548.x
Subject(s) - ecdysterone , ecdysone , hydrogen peroxide , chemistry , oxidase test , cholesterol oxidase , enzyme , pregnenolone , biochemistry , oxygen , steroid , stereochemistry , organic chemistry , hormone
Ecdysone oxidase oxidizes 3‐hydroxysteroids of the ecdysteroid type irreversibly to 3‐dehydro derivatives. The hydrogen of the steroid is transferred by the enzyme to oxygen which is reduced to hydrogen peroxide. Ecdysone oxidase is relatively specific for ecdysone and ecdysterone. Apparent Michaelis constants for these two physiological substrates are 98 and 31 μM, respectively. Cholesterol oxidase and 3α‐hydroxysteroid and 3β‐hydroxysteroid dehydrogenases which catalyze similar reactions are unable to oxidize ecdysteroids.