Characterization of myosin from normal dog heart.

Although many physicochemical studies of skeletal myosin have been reported (l-4), comparatively few comparable studies have been made of cardiac myosin (5-7). The assumption that the myosins derived from skeletal, smooth, and cardiac muscle are identical (8) is not based upon any single rigorous comparative study. This laboratory is presently devoted to a systematic study of myocardial metabolism in dogs and man under various conditions of health and disease (9). The present communication is devoted to the physicochemical characterization of myosin isolated from the hearts of normal dogs. Preliminary reports of this work have been published elsewhere (10, 11).