1) The actomyosin preparation isolated from the squid mantle muscle was subjected to electrophoresis at an ionic strength of 0.4 and pH 7.2 (NaCl-phosphate buffer), three components with the mobilities, -5.1×, -4.1×, and -3.2×(ascending limb), -4.4×, -3.7×, and -3.0×10-6 cm2./V. sec. (descending limb), respectively, being observed usually. It appeared a characteristic of the squid actomyosin-like protein that the electrophoretic homogeneity is less readily attained by isolating procedure, while actomyosins of the rabbit and carp readily give a single pattern. However, in few examples of the squid, preparations showing a single peak of the fastest were obtained.
2) By comparing the electrophoretic patterns of different samples obtained after different periods of dialysis, and results of various experiments, a tentative interpretation was presented as follows:
Component 1, the fastest, is the actomyosin-like protein of the squid muscle, which shows high viscosity and its ATP-response. The actomyosin-like protein of the squid is higher in mobility than the ones of rabbit and carp actomyosins.
Component 2, the middle-speeded, is an artefact which is derived from Component 1 during dialysis and electrophoresis. Component 2 might correspond to tropomyosin.
With the nature of Component 3, the slowest, no reasonable explanation is obtained.
