High affinity of various smooth muscle myosins for skeletal F-actin demonstrated by enzyme kinetics and electron microscopy.
Myosins isolated from mixed rabbit skeletal muscle and several smooth muscles differ with respect to the rate of ATP hydrolysis and the degree of inhibition of the potassium-activated ATPase activity at saturating actin concentrations. Kinetic studies indicate that smooth muscle myosins are tightly bound to skeletal F-actin in the presence of ATp. This observation led to the hypothesis that ATP is a poor dissociating agent for smooth muscle myosin and skeletal F-actin. The kinetic interpretation was verified by electron microscopic observations of myosin binding to F-actin filaments in the presence of ATP.
D000199:Actins / Q000378:metabolism*; D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000818:Animals; D002339:Carotid Arteries; D027682:Cation Transport Proteins; D002645:Chickens; D004789:Enzyme Activation; D005895:Gizzard, Avian; D007700:Kinetics; D009130:Muscle, Smooth / Q000201:enzymology*; D009132:Muscles / Q000201:enzymology*; D009218:Myosins / Q000378:metabolism*; D011189:Potassium Chloride / Q000494:pharmacology; D011817:Rabbits; D013270:Stomach / Q000201:enzymology; D013552:Swine
D000199:Actins; D027682:Cation Transport Proteins; D011189:Potassium Chloride; D000251:Adenosine Triphosphatases; C022761:potassium transporting ATPase; D009218:Myosins