Action of Co-zymase as the Specific Co-enzyme of Lactic Dehydrogenase from Heart Muscle

Abstract

EARLIER work on the mechanism of enzymatic dehydrogenation has shown that, in presence of a thermolabile apo-dehydrogenase of protein character, co-zymase takes up hydrogen from a substrate and is thereby reduced to a dihydro-form¹; the dehydrogenation of alcohol may be represented by the equationwhere D^A is the specific alcohol apo-dehydrogenase and Co^I co-zymase. The apo-dehydrogenases are specific with respect to substrates and to one or other of the two known co-dehydrogenases, co-zymase (Co^I) or Warburg's co-ferment (Co^II)². Recently, we showed that lactic apo-dehydrogenase from heart muscle and alcohol apo-dehydrogenase from yeast are not identical, but both form active holo-dehydrogenases only with Co^I and not with Co^{II 3}.