Some Properties of Human Skeletal Muscle Creatine Kinase

Abstract

Creatine kinase has been purified from human skeletal muscle. The properties of the human enzyme are similar to those of the enzyme from rabbit muscle. The molecular weight was determined as approximately SO 000 with a probable two reactive sulphydryl groups per molecule. Manganous (II) ion was almost as effective as magnesium as the activating metal ion, and calcium and cobalt could also act in this capacity. Under standardized conditions the nucleotide specificity was ADP > dADP > IDP > GDP > UDP > XDP in the reverse reaction. No hydrolytic activity was observed with ATP.