抄録
The viscosity change of myosin A concentrated solution with or without other com-ponents was measured as the incubation time elapsed at 30°C.
The viscosity of myosin A solution increased, but that of F-actin solution did not. The shear stress at 0.04 sec-1 was not increased to 1.0 dyne/cm2 in the former, but in the latter was below 0.5 dyne/cm2.
The viscosity of myosin B solution increased slightly, but that of native tropomyosin-free myosin B solution decreased remarkably. In both the shear stress at 0.04 sec-1 was greater than or equal to 15 dynes/cm2.
The speed of the viscosity increase in the presence of 3mM pyrophosphate and 3mM MgCl2 was higher in concentrated solution of myosin B than in that of native tropomysin-free myosin B. The shear stress at 0.04 sec-1 after 6 hr at 30°C was 11.5 and 8.2 dynes/cm2, respectively.
The effect of native tropomyosin and actin on the viscosity change was discussed.
