The dissociation of myosin by heat coagulation

When myosin solutions were coagulated at 53°, pH 6.2, 8–18% of the protein remained in solution. This material could be divided by dialysis into two parts: (a) a myosin-like fraction, P, comprising 4–13% of the myosin and containing a well defined major component P1 together with some heavy disperse material; (b) A low-molecular-weight, water-soluble fraction, D, containing three components D1, D2, D3 in the approximate proportions 4:5:1. The adenylic deaminase activity of P was 3–4 times greater than that of myosin while that of D was low. D2 contained C-terminal isoleucine to the extent of one end-group in a particle weight of 20–30,000. The effect on the coagulation products of variables such as myosin concentration, temperature, pH, etc., has been studied.