The effect of time, 2-mercaptoethanol and inhibitors of proteases on isolation of cardiac myosin and its properties

Myosin was isolated from the ventricular myocardium of adult rats and the effect of time, 2-mercaptoethanol and inhibitors of proteases was investigated on its properties. It was found that the storage of cardiac muscle up to 4 hours does not influence the myosin ATPase, the electrophoretic pattern of light chains of myosin or the pattern of peptides produced by digestion of myosin with chymotrypsin. Neither does the presence of pepstatin and phenylmethyl sulfonylfluoride during myosin preparation influence the activity of myosin ATPase. It was found that the presence of 2-mercaptoethanol during myosin preparation enhances myosin ATPase of the product. This myosin was more stable when kept at 4 degrees C for four days.