Diaphorase (coenzyme factor)

Abstract

Diaphorase was prepared from pea and bean seedlings, from the common white potato and from a mould culture predominantly Rhizopus (sp.) by extracting crushed material with Na2HPO4. It was purified by precipitation with ammonium sulphate. Diaphorase was also prepared from pig heart muscle as above and purified more extensively by CO2-acetone precipitations. Peas contained 1/6 and beans 1/10 as much diaphorase as pig heart; potatoes and mould contained a negligible amt. Estimations were made both by the Thunberg methylene blue and by the spectrophoto-metric techniques. These methods showed that plant diaphorase was a specific oxidant for dihydrocodehydrase I and was extremely unstable. By a fermentation technique it was shown that pig heart diaphorase did not accelerate the reduction of simple quinones by dihydrocodehydrase I and might be absent in quinone-containing respiratory systems.