Calcium-sensitivity of pig-carotid-actomyosin ATPase in relation to phosphorylation of the regulatory light chain.
Ca2+-dependent phosphorylation of the 20000-Mr regulatory light chain was found to be a necessary condition for the Ca2+-sensitivity of the Mg2+-dependent ATPase activity and superprecipitation of pig carotid actomyosin. Actin-myosin interaction independent of phosphorylation and Ca2+ (ATPase activity and superprecipitation) were demonstrated in aged actomyosin preparations and in preparations from which the regulatory light chains were removed by papain digestion.
D000205:Actomyosin / Q000378:metabolism*; D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000818:Animals; D002118:Calcium / Q000494:pharmacology*; D002339:Carotid Arteries / Q000201:enzymology; D007700:Kinetics; D046911:Macromolecular Substances; D008274:Magnesium / Q000494:pharmacology; D008970:Molecular Weight; D009131:Muscle, Smooth, Vascular / Q000201:enzymology*; D010766:Phosphorylation; D013552:Swine
D046911:Macromolecular Substances; D000205:Actomyosin; D000251:Adenosine Triphosphatases; D008274:Magnesium; D002118:Calcium