コイ筋肉のトロポミオシンについて

抄録

Tropomyosin was extracted with 1M potassium chloride solution from the dried muscle powder of carp and purified by isoelectric precipitation, ammonium sulfate fractionation and gel filtration using Sephadex G-200.
The ultraviolet spectrum of the carp tropomyosin showed the absence of a nucleotide contaminant. The absorbance for a 0.1% solution of 1cm path length at 278 mμ was 0.290. The viscometric properties of carp tropomyosin were similar to those of rabbit skeletal tropomyosin. Intrinsic viscosity of both tropomyosins was determined to be 0.36 dl/g. On SDS-polyacrylamide gel electrophoresis, carp tropo-myosin showed a single band with similar mobility to the faster one of two bands present in rabbit tropomyosin. Although tropomyosin inhibited the Mg²⁺-ATPase activity of desensitized carp actomyosin at 2m_M Mg²⁺-ATP in the presence and absence of Ca²⁺, it had no effect on the Ca²⁺-sensitivity. In the presence of carp troponin, tropomyosin conferred Ca²⁺-sensitivity on the Mg²⁺-ATPase and super-precipitation of desensitized actomyosin.
It was suggested that the mechanisms and functions of the regulatory system in carp muscle were essentially the same as those of the rabbit.