Studies on the Role of Light and Heavy Chains in Myosin Adenosine Triphosphatase

The release of light and heavy components from myosin by urea, alkali, and heat denaturation was early reported (Tsao, 1953; Locker, 1956; Kominz et al., 1959). After long controversy, there now seems to be general agreement that myosin (470,000 mol wt) comprises an axial core of two heavy polypeptide chains (205,000 mol wt) that terminate in a globular region containing approximately three light chains of average mol wt about 20,000 (Gershman et al., 1966, 1969; Dreizen et al., 1967; Locker and Hagyard, 1967a, b; Lowey et al., 1969; Gazith et al., 1970; Weeds and Lowey, 1971). The globular head of myosin appears to contain symmetric halves of subfragment-1 (Slayter and Lowey, 1967; Trotta et al., 1968; Lowey et al., 1969), each of which contains one light chain and a remnant of one heavy chain (Trotta et al., 1968).