Characteristics of Lactic Dehydrogenases in Human Erythrocytes

Abstract

The authors have studied erythrocyte protein fractions with lactic dehydrogenase activity by means of electrophoresis on cellulose acetate strips and chromatography on DEAE-Sephadex. Five LDH fractions, stained with tétrazolium salts, were detected by means of electrophoresis. Their relative proportions were determined by the optical test, after identification with ultraviolet light and elution. The chromatogram on DEAE-Sephadex, obtained with a sinusoidal gradient, consisted of five LDH peaks. The non-absorbed fraction was found to be non- homogeneous on electrophoretic examination and is considered to be a technical artifact. The peak immediately preceding the hemoglobin also appeared to be non- homogeneous and composed of two electrophoretic fractions, IV and V. In contrast, the peaks following hemoglobin were homogeneous and corresponded to electrophoretic fractions III, II and I. The resistance to inactivating agents (heat and trypsin) was also tested for the various fractions isolated.