PURIFIED MUSCLE PROTEINS AND THE WALKING RATE OF ANTS

Abstract

The rate of hydrolysis of adenosine triphosphate (ATP) added to a purified protein system of actomyosin obtained from rabbit skeletal muscle or reconstituted actin and myosin obtained separately was measured over a temperature range from 300to 00C. By maintaining a low ionic strength it was possible to demonstrate that superprecipitation occurred over the entire temperature range. Approximately linear curves were obtained at the higher and lower temperatures and the calculated activation energies were 12 kcal and 25 kcal with a rapid transition occurring at about let from one linear phase to the other. Comparison of the data for the myosin and actomyosin catalyzed hydrolysis and the data for ant walking lead to the conclusion that the rate limiting reaction in the walking rate of ants is the hydrolysis of ATP catalyzed by actomyosin.