Differential scanning calorimetric studies on myosin and actin.

This review is concerned with the application of the method of differential scanning calorimetry (DSC) to structural and functional studies of myosin and actin--the main two proteins of muscles and many other systems of biological motility. The domain organization of these proteins as revealed by DSC is considered. Data are presented on the conformational changes which occur in the myosin head and in F-actin due to the formation of the ternary complexes with ADP and Pi analogs (such as orthovanadate, beryllium fluoride, or aluminum fluoride). Recent data on the application of DSC to studies on the interaction of F-actin with myosin heads and with tropomyosin are also considered. It is concluded that DSC offers a new and promising approach to probe the structural changes which occur in the myosin head and in F-actin during ATP hydrolysis and due to interaction of these proteins with each other.