Purification and Some Properties of Porcine Erythrocyte Adenylate Kinase

Abstract

Porcine erythrocyte adenylate kinase showed three components, AKa, AKb and AKc, designated on the basis of the distance of migration from their origin to the anode in starch gel electrophoresis. By isoelectrofocusing, 96% of the total erythrocyte adenylate kinase focused at pH 9.25, and this predominant enzyme form corresponded to AKa in starch gel electrophoresis. The predominant enzyme form, AKa, was purified at approximately 31, 000 fold from the porcine erythrocyte in an overall yield of 45% by affinity chromatography on a column of Blue Dextran-Sepharose 4B, substrate elution from a column of phosphocellulose, and by isoelectrofocusing. The purified AKa had a specific activity of 2, 100 units per mg of enzyme and migrated in gel electrophoresis as a single band having a molecular weight of 21, 500. The amino acid composition of AKa was the same as that of the skeletal muscle enzyme. Peptide mapping showed a correspondence of all spots of the tryptic peptides from the erythrocyte and skeletal muscle enzyme preparations. These results strongly suggest that the predominant adenylate kinase in porcine erythrocyte is identical to porcine skeletal muscle adenylate kinase.