/. Biochem., 80, 611-619 (1976)
Cardiac Myosin from Pig Heart Ventricle Purification and Enzymatic Properties Umeji MURAKAMI, Koki UCHIDA, and Toshiaki HIRATSUKA Department of Chemistry, Asahikawa Medical College, Kaguracho, Asahikawa, Hokkaido 071-01 Received for publication, February 17, 1976
A method is described for the preparation of high purity myosin from the left ventricle of pig heart. The purified myosin was free from nucleic acid, actin, tropomyosin, troponin, the 150,000 molecular weight protein and other contaminants. Analyses of subunits in the purified myosin were carried out on 3.5% acrylamide gel with 0.1% SDS. Of the total protein present in myosin, 11.3% was in the light chains; light chain 1 (Ld), 5.9% and light chain 2 (LCE), 5.4%. Urea gel elctrophoresis of the purified myosin showed three closely spaced bands corresponding to the 20,000 dalton, the charge-modified 20,000 dalton and the phosphorylated 20,000 dalton components. The properties of the Cat+-activated and K+-activated ATPases [EC 3.6.1.3] of the purified myosin were also studied. The Km values were 27 and 55 fiM and the Fm»x values were 0.263 and 0.317 /imole Pi/mg/min for the Ca1+activated and Reactivated ATPases, respectively. The pH-activity profiles and the effects of SH modification were of the skeletal myosin type except that the activities were lower.
It is well established that cardiac myosin is composed of two large polypeptide chains, heavy chain (HC), and two classes of small polypeptide chains, light chain 1 (LCi) and light chain 2 (LCi) ( 1 - 9 ) , whereas fast skeletal muscle myosin possesses two heavy chains and three classes of light chains (10—16). Cardiac myosin from mammalian heart resembles slow skeletal muscle myosin in its substructure and possesses a lower ATPase [EC 3.6.1.3] activity Abbreviations: SDS, sodium dodecyl sulfate ; DTT, dithiothreitol; PCMB, £-chloromercuribenzoate; DTNB, 5,5'-dithiobis-
Cardiac Myosin from Pig Heart Ventricle Purification and Enzymatic Properties Umeji MURAKAMI, Koki UCHIDA, and Toshiaki HIRATSUKA Department of Chemistry, Asahikawa Medical College, Kaguracho, Asahikawa, Hokkaido 071-01 Received for publication, February 17, 1976
A method is described for the preparation of high purity myosin from the left ventricle of pig heart. The purified myosin was free from nucleic acid, actin, tropomyosin, troponin, the 150,000 molecular weight protein and other contaminants. Analyses of subunits in the purified myosin were carried out on 3.5% acrylamide gel with 0.1% SDS. Of the total protein present in myosin, 11.3% was in the light chains; light chain 1 (Ld), 5.9% and light chain 2 (LCE), 5.4%. Urea gel elctrophoresis of the purified myosin showed three closely spaced bands corresponding to the 20,000 dalton, the charge-modified 20,000 dalton and the phosphorylated 20,000 dalton components. The properties of the Cat+-activated and K+-activated ATPases [EC 3.6.1.3] of the purified myosin were also studied. The Km values were 27 and 55 fiM and the Fm»x values were 0.263 and 0.317 /imole Pi/mg/min for the Ca1+activated and Reactivated ATPases, respectively. The pH-activity profiles and the effects of SH modification were of the skeletal myosin type except that the activities were lower.
It is well established that cardiac myosin is composed of two large polypeptide chains, heavy chain (HC), and two classes of small polypeptide chains, light chain 1 (LCi) and light chain 2 (LCi) ( 1 - 9 ) , whereas fast skeletal muscle myosin possesses two heavy chains and three classes of light chains (10—16). Cardiac myosin from mammalian heart resembles slow skeletal muscle myosin in its substructure and possesses a lower ATPase [EC 3.6.1.3] activity Abbreviations: SDS, sodium dodecyl sulfate ; DTT, dithiothreitol; PCMB, £-chloromercuribenzoate; DTNB, 5,5'-dithiobis-
