Isolation of creatine kinase BB isoenzyme with high specific activity and adequate purity for radioimmunoassay from human placenta on preparative polyacrylamide gel electrophoresis.

This report describes the procedures for isolation of creatine kinase BB isoenzyme (CK-BB) from human placenta on preparative polyacrylamide gel electrophoresis. 2.5 mg of CK-BB was purified from a 100-g portion of the human placenta, which had a mean specific activity of 957 kU/g and a mean yield of 16%. The placenta CK-BB exhibited single protein bands on several electrophoretic techniques. In addition, both of the placenta and brain CK-BB preparations were individually iodinated and the identical immunological properties of both the CK-BB preparations were confirmed in radioimmunoassay.