Abstract
Four isoenzymes of creatine kinase (CK) are present in human serum. Three isoenzymes, CK-MM, CK-MB and CK-BB, were found in the cytoplasmic fraction, and the other, mitochondrial CK (m-CK), was located in the mitochondrial fraction. We describe here the abnormal fractions detected by electrophoresis for CK isoenzyme analysis. Creatine kinase-linked immunoglobulin (Macro-CK type 1), high molecular weight m-CK (Macro-CK type 2), m-CK, adenylate kinase (AK), and abnormal CK-MM subbands were detected by electrophoresis as abnormal CK zymogram. Macro-CK type 1 could be detected in the serum of the patients who suffered from hereditary muscular disorders and malignant tumors, and the globulins that bound to the CK could be identified by immunological techniques. The physico-chemical properties of the Macro-CK type 1 were : activation energy was below 75 kJ/mol, it was stable under heat treatment, and its biological activity was not inhibited by CK-M antibodies. On the other hand, Macro-CK type 2 was a polymer of m-CK, and was detected in the sera of the patients who suffered from malignant tumors. The physico-chemical properties of the Macro-CK type 2 were: activation energy was above 75 kJ/mol, it remained heat stable, and there was no inhibition by the CK-M antibodies. Abnormal zymogram created by AK could be discriminated by the exclusion of creatine phosphate in the substrate solution. CK-MM had 3 subbands detected in human serum by extension of electrophoresis, we classified the abnormal CK-subbands into 2 groups.
