On the catalytic function of heart flavoprotein

Abstract

Heart flavoprotein catalyzed the oxidation of the dihydropyridinenucleotides by "carriers" such as methylene blue. The mechanism of the catalysis involved a cycle of reduction of the flavoprotein by dihydro-coenzyme and oxidation of its leuco form by the "carrier." Leucoflavoprotein was sluggishly autoxidizable. Under optimum conditions each molecule of flavoprotein catalyzed the oxidation of 8500 molecules of difaydrocoenzyme 1 per min. Coenzyme Tactor (diaphorase) was considered to be identical with heart flavoprotein. Whereas the former was found in association with insoluble particles, the latter was separated from the particles and brought into solution.