[Action of heavy water on actomyosin pellicular filaments]

Deuterium oxide (D2O) prolongates the contractile ability of actomyosin threads by 85%. The contraction of actomyosin threads decreases in the presence of D2O by 28%. D2O decreases neutral red sorption by actomyosin threads. The limiting dye sorption (A infinity) decreases by 45 and 31% within the ranges of weak and high concentrations, resp. Thus, deuterium oxide may affect the conformation of protein molecules.