Stimulatory effect of calponin on myosin ATPase activity.
Calponin, a calmodulin-binding protein of smooth muscle that inhibits the actin-myosin interaction by binding to actin, was shown to bind to myosin and to stimulate the ATPase activity of myosin to some extent. Actin abolished this myosin-linked, stimulatory effect of calponin. Ca(2+)-calmodulin affected neither the myosin-binding activity nor the stimulatory effect of calponin. We further presented a few data which suggest that calponin may exert regulatory activity toward myosin in quite a different way from caldesmon, another smooth muscle protein that binds to myosin, actin, and calmodulin.
Lin
Y
Y
Department of Pharmacology, Gunma University School of Medicine.
Ye
L H
LH
Ishikawa
R
R
Fujita
K
K
Kohama
K
K
D000818:Animals; D017301:Ca(2+) Mg(2+)-ATPase / Q000378:metabolism; D002135:Calcium-Binding Proteins / Q000494:pharmacology*; D002148:Calmodulin-Binding Proteins / Q000494:pharmacology; D002645:Chickens; D066298:In Vitro Techniques; D007700:Kinetics; D008840:Microfilament Proteins; D009124:Muscle Proteins / Q000494:pharmacology; D009130:Muscle, Smooth / Q000187:drug effects / Q000201:enzymology; D009132:Muscles / Q000187:drug effects / Q000201:enzymology; D009218:Myosins / Q000378:metabolism*; D000096985:Calponins
D017301:Ca(2+) Mg(2+)-ATPase; D002135:Calcium-Binding Proteins; D002148:Calmodulin-Binding Proteins; D008840:Microfilament Proteins; D009124:Muscle Proteins; D009218:Myosins; D000096985:Calponins