Immobilization of actin and myosin

Using glutaric dialdehyde, the muscle proteins myosin, actin, actomyosin and heavy meromyosin subfragment-1 (S-1) have been immobilized on capron fibers. The ATPase activity of myosin and its capability to interact with actin have been preserved whereas the ATPase activity of its subfragment decreased significnatly. Immobilization on capron fibers changes the pH dependence of the ATPase activity of myosin and of S-1 shifting the maximum towards the acid zone (pH 5.5) and increases the thermal stability of the enzyme. Calcium ions produce a stimulatory effect on ATPase; Mg2+ions yield no effect on myosin and S-1 but enhance the activity in the case of immobilized actomyosin though to a lesser degree than the ions of Ca2+. Immobilized actin retains its ability to form actomyosin complex.