Isolation and molecular properties of creatine kinase from carp white muscle

Abstract

1. 1. Three creatine kinase isoenzymes analogous to the MM, MB and BB forms of enzyme in higher vertebrates, are present in adult carp skeletal muscles, heart and brain. 2. 2. A procedure is described to isolate the MM isoenzyme from carp white muscle. Purity of the enzyme preparations is established from starch gel electrophoresis and ultracentrifugation analysis. 3. 3. A 6-fold purification yields pure enzyme with low catalytic activity compared to that of rabbit muscle enzyme. The validity and implications of this finding are discussed. 4. 4. The molecular weight, diffusion and sedimentation coefficients as well as amino acid composition of carp MM creatine kinase have been determined. 5. 5. Peptide maps of the rabbit and carp MM enzymes are compared. As a first approximation, a maximum of 75% similarity in peptides may be expected. 6. 6. Eight cysteine residues are found on amino acid analysis, two of which are essential to catalytic activity.