[Effect of regulatory light chains of myosin on aggregation of its subfragment-1]

Chymotryptic (Ch-Cl) and Mg(2+)-papain subfragments 1 of (Mg-Cl) skeletal myosin has been studied. Mg-Cl is known to differ from Ch-Cl by the presence of the regulatory light chain (RLC) and elongated heavy chain including C-end hinge segment. Experimental data prove the decisive part of coordination bondings with bivalent cations in stabilization of RLV on myosin head hinge segment. Hydrophobic interactions are also significant that is evidenced by the intensive aggregation between subfragment Mg-Cl molecules, after RLC dissociation.