Genetic Variant of Human Erythrocyte Malate Dehydrogenase

MALATE dehydrogenase exists in two distinct forms in a variety of mammalian tissues, one of which is in the cytoplasm as a soluble or supernatant enzyme and the other is tightly bound to the mitochondria1. These two forms have different chemical, physical and kinetic properties2–4 and each has a characteristic electrophoretic pattern5. Unlike most tissues erythrocytes possess only cytoplasmic malato dehydrogenase, as would be expected in the absence of mitochondria. This report concerns an inherited electrophoretic variant of erythrocyte (supernatant) malate dehydrogenase which was found in a survey of haemolysates prepared from 2,910 individuals, of whom 1,440 were white and 1,470 were North American Negroes. All were unrelated so far as is known, and consisted of unselected patients and personnel of three Buffalo hospitals. In the family investigations, both haemolysates and leucocyte extracts were electrophoresed.