Characteristics of ATPase activity and the subunit composition of myosin in the conduction system of bovine heart.
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 Ca2+-activated ATPase activity was atrial greater than specialized myocardial tissue greater than 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 V3 isomyosin and showed no difference from ventricular myocardial tissue on pyrophosphate gel.
D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000818:Animals; D000252:Calcium-Transporting ATPases / Q000378:metabolism; D002417:Cattle; D004591:Electrophoresis, Polyacrylamide Gel; D006325:Heart Atria / Q000378:metabolism; D006352:Heart Ventricles / Q000378:metabolism; D007527:Isoenzymes / Q000378:metabolism*; D009206:Myocardium / Q000378:metabolism*; D009218:Myosins / Q000378:metabolism*; D011690:Purkinje Fibers / Q000378:metabolism; D051381:Rats
D007527:Isoenzymes; D000251:Adenosine Triphosphatases; D009218:Myosins; D000252:Calcium-Transporting ATPases