Studies on chicken actomyosin I. Effect of storage on muscle enzymic and physico‐chemical properties

Experiments were conducted to study the effect of storing broiler chicken muscle at 25°C on certain properties of actomyosin of the pectoralis major. Storage for 3 h or more resulted in the Mg2+‐activated ATPase of actomyosin becoming less sensitive to inhibition by increasing concentrations of KCl and in an increased rate of superprecipitation of the complex. The analytical ultra‐centrifuge pattern of the actomyosin of stored muscle differed from that of fresh muscle. Some evidence was obtained for the observed changes being partly dependent upon the pH of the muscle used as the source of actomyosin.