Effects of pyrophosphate and divalent metal ions (Mg2+, Ca2+) on carp actomyosin

Effects of pyrophosphate and divalent metal ions (Mg2+, Ca2+) on actomyosin were examined by viscosity measurement and electron microscopy. Various media were added to actomyosin solution, and the mixtures were applied to the above examination. In the case of protein concentration of about 3mg/ml, the viscosity decreased only in the medium containing 10-4M pyrophosphate and 5mM Mg2+ On the other hand, in the case of protein concentration of 5.2mg/ml, the decrease in viscosity was recognized in all media containing 10-4M pyrophosphate, and it was remarkably accelerated by the addition of Mg2+ (5mM, 25mM). The association of actin and myosin was obviously recognized in a medium by a greater decrease in the viscosity.