 Heavy meromyosin

Heavy meromyosin (HMM) is the larger of the two fragments obtained from the muscle protein myosin II following limited proteolysis by trypsin or chymotrypsin.HMM contains two domains S-1 and S-2, S-1 contains is the globular head that can bind to actin while the S-2 domain projects at and angle from light meromyosin (LMM) connecting the two meromyosin fragments.