Crayfish myosin has no Ca2+-dependent regulation in actomyosin.
1. Crayfish myosin B lost Ca2+-dependent regulation in superprecipitation upon addition of pure rabbit skeletal F-actin. 2. Actomyosin reconstituted from crayfish myosin and pure rabbit skeletal F-actin showed both Ca2+-dependent regulation in superprecipitation and Mg2+-ATPase activity upon addition of native tropomyosin prepared from crayfish or rabbit skeletal muscles. Also, superprecipitation of this actomyosin was induced by ITP without Ca2+-dependent regulation, as is the case in rabbit skeletal actomyosin. 3. Actomyosin reconstituted from crayfish native thin filament and crayfish or rabbit skeletal myosins showed Ca2+-dependent regulation. 4. These findings indicate that crayfish myosin is similar to rabbit skeletal myosin and different from chicken gizzard myosin in regulatory function.
D000199:Actins / Q000378:metabolism; D000205:Actomyosin / Q000378:metabolism*; D000818:Animals; D003400:Astacoidea / Q000378:metabolism*; D002118:Calcium / Q000494:pharmacology*; D002122:Calcium Chloride / Q000494:pharmacology; D004533:Egtazic Acid / Q000494:pharmacology; D007700:Kinetics; D009132:Muscles / Q000378:metabolism; D009218:Myosins / Q000378:metabolism*; D011817:Rabbits
D000199:Actins; D004533:Egtazic Acid; D000205:Actomyosin; D009218:Myosins; D002122:Calcium Chloride; D002118:Calcium