Metalloenzymes and Myocardial Infarction

PREVIOUS studies in this laboratory have shown that the concentration of copper in serum is considerably increased after acute myocardial infarction.1 This change is proportional to an increase in ceruloplasmin, the copper protein of human serum, and its capacity to oxidize paraphenylenediamine.2 In the pursuit of these studies, the concentration of zinc and the activity of zinc enzymes in human serum have been found to be altered markedly in myocardial necrosis.Lactic dehydrogenase has recently been shown to be a zinc enzyme,3 and malic dehydrogenase also appears to be a metalloenzyme.4 These enzymes require coenzyme 1 (diphosphopyridine nucleotide) for their . . .