1977 Volume 43 Issue 3 Pages 329-334
Actin was isolated from the smooth adductor of scallop Patinopecten yessoensis as follows. The crude natural actomyosin was prepared as reported previously, and dissolved in 0.6M KCl•5 mM 2-mercaptoethanol 25 mM Tris-HCl buffer pH 7.4. Up to 5mM ATP was added to the solution, and the mixture was gently stirred for several minutes at 0°C. Then the mixture was centrifuged at 10, 000×g for 30 min to spin down the precipitate consisting mainly of myosin, tropomyosin, and paramyosin. The supernatant thus obtained consisted almost exclusively of actin. This actin showed a s020.w of 3.30S, and a molecular weight of about 47, 000 daltons. It was demonstrated to be composed of a single polypeptide.The intrinsic viscosity was 0.20 dl/g in the G-form and 1.6 dl/g in the F-form. This scallop actin was rich in Glu, Asp and Ala, and poor in Trp, Cys/2 and His. Except for the lower intrinsic viscosity in the F-Form, this actin is very similar to actins from various other sources.