[Purification and identification of human cardiac myosin light chains]

Normal human left ventricular myocardium was obtained within 5 hours after death. Crude cardiac myosin was extracted from the myocardium by the method of Schossler, and cardiac myosin light chains (CMLC) were purified by isoelectric precipitation, fast protein liquid chromatography and preparative SDS-PAGE, respectively. The three methods were compared. The Ca2(+)-activated ATPase activity of cardiac myosin was 101.4 nmole Pi/mg/min. Molecular weights of CMLCI (24500) and CMLC II (20,000) were identified by analytical SDS-PAGE. All of the results mentioned above were consistent with data reported in the literature. An analytical electrophoresis test of the stability of CMLC stored at -20 degrees C demonstrated that liquid CMLC at long storage times or lower concentrations was easily degraded.