Scallop striated tropomyosin prepared by a new method

A large amount of tropomyosin was quickly prepared from scallop striated mu scle by the method combining ammonium sulfate fractionation in the presence of Mg2+-ATP and subsequent dialysis. The yield of tropomyosin by this meth od was about four times higher than that by conventional method. The tropom yosin thus prepared showed essentially the same activity as ordinary prepar ation, e.g., it depressed the Mg2+-ATPase activity of rabbit skeletal actom yosin by 25%, whereas no effect; on that of reconstituted scallop actomyosi n was observed. This new method for preparing tropomyosin characterized by its simplicity and rapidity is expected to be applicable to different kinds of muscle.