Creatine phophoryl tranferase and phosphoglyceraldehyde dehydrogenase in iodoacetate poisoned muscle

Abstract

By extraction of iodoacetate poisoned muscles and subsequent fractionation and assay for enzymic activity, it has been shown that in such muscles phosphoglyceraldehyde dehydrogenase is completely inhibited, while creating phosphoryltransferase is not affected at all, even though in vitrol the latter enzymme is nearly as susceptible to such inhibitions as is the former. This result is explained by the finding that several substances can protect creatine phosphoryltransferase against the action of iodoacetate. In decreasing order of effectiveness, these are: PC, ATP > ADP, PP > AMP > P, while arsenate and creatine to give no protection. These findings eliminate the doubts that have recently been expressed as to the explanation of the phosphocreatine splitting in iodoacetate poisoned muscle, and thereby against the physiological significance of the Lohmann-reaction and against the customary views on phosphocreatine as a phosphagen.