Characteristics of ATPase activity and the subunit composition of myosin in the conduction system of bovine heart

• Published in: FEBS Letters Vol. 178; no. 2; pp. 209 - 212
• Main Authors: Tamura, Yoshiyuki, Nishimoto, Tetsuo, Miyakami, Sciji, Sako, Harunobu, Saito, Ken, Mori, Hiroyoshi
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 10.12.1984; Wiley; Elsevier
• Subjects: Adenosine Triphosphatases; Adenosine Triphosphatases - metabolism; adenosinetriphosphatase; Analytical, structural and metabolic biochemistry; Animals; ATPase; Biological and medical sciences; Calcium-Transporting ATPases; Calcium-Transporting ATPases - metabolism; Cardiac conduction system; Cattle; Contractile proteins; Electrophoresis, Polyacrylamide Gel; Fundamental and applied biological sciences. Psychology; heart; Heart Atria; Heart Atria - metabolism; Heart Ventricles; Heart Ventricles - metabolism; Holoproteins; Isoenzymes; Isoenzymes - metabolism; Myocardium; Myocardium - metabolism; Myosin; Myosin isoenzyme; Myosin light chain; Myosins; Myosins - metabolism; Proteins; Purkinje Fibers; Purkinje Fibers - metabolism; Rats; Specialized myocardial tissue; Cardiac conduction system; Myosin isoenzyme; Specialized myocardial tissue; ATPase; Myosin; Myosin light chain; Heart; Enzyme; Heart ventricle; Subunit; Vertebrata; Mammalia; Enzymatic activity; Myocardium; Artiodactyla; Beef; Light-Peptide chain; Ungulata
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/0014-5793(84)80602-X

The ATPase activity, light chains and isoenzymes of myosin from specialized myocardial tissue (the A-V node, bundle of His, and right and left bundle branches) of bovine heart were compared with those of atrial and ventricular myosins. The order of Ca 2+-activated ATPase activity was atrial ⪢ specialized myocardial tissue ⪢ ventricular myosin. SDS-polyacrylamide gel electrophoresis showed that myosin from the specialized myocardial tissue contained the light chains of both atrial and ventricular myosins. On the other hand, the specialized myocardial tissue contained one V 3 isomyosin and showed no difference from ventricular myocardial tissue on pyrophosphate gel.