Milestone in Physiology The Early History of the Biochemistry of Muscle Contraction

Since antiquity, motion has been looked upon as the index of life. The organ of motion is muscle. Our present understanding of the mechanism of contraction is based on three fundamental discoveries, all arising from studies on striated muscle. The modern era began with the demonstration that contraction is the result of the interaction of two proteins, actin and myosin with ATP, and that contraction can be reproduced in vitro with purified proteins. The second fundamental advance was the sliding filament theory, which established that shortening and power production are the result of interactions between actin and myosin filaments, each containing several hundreds of molecules and that this interaction proceeds by sliding without any change in filament lengths. Third, the atomic structures arising from the crystallization of actin and myosin now allow one to search for the changes in molecular structure that account for force production. Mostly I will discuss how biochemical studies from 1941 to 1972 contributed to our understanding of contraction. I shall particularly focus on two aspects of the history: the work of the Szeged school, since the papers in the Studies from the Institute of Medical Chemistry University Szeged were and are not readily available; 1