Actomyosin-like protein isolated from mammalian brain

A protein with characteristics similar to actomyosin has been isolated from whole brain of rat and cat. It is soluble in 0.6 molar potassium chloride and insoluble in 0.1 molar potassium chloride. It superprecipitates with magnesium ions and adenosine triphosphate. It has adenosine triphosphatase activity stimulated by either magnesium or calcium ions. Both superprecipitation and adenosine triphosphatase activity are inhibited by p-chloromercuribenzoate and Mersalyl but not by ouabain

The nature of the contractile protein isolated from brain / S. Puszkin, E. Puszkin, D. D. Clarke, and S. Berl. Coll of Phys. and Surgeons., Columbia Univ., N.Y. 10032

We have described the isolation from brain of a Mg++/Ca++-ATPase resembling muscle actomyosin (Sci. 12 1 1701 1968). Like myofibrils (Perry and Grey 1 Biochem. J. 64, 184, 1956), the ATPase activity isolated from rat and cat brain is dependent upon the cone. of ATP and cation. When the conc. of ATP exceeds that of Mg++ 1 enzyme activity is inhibited. With increasing conc. of Mg++ 1 the optimum conc. of ATP also increases. This does not occur with Ca++ . Polyethylenesulfonate( PS)(I0-6M)causes the splitting of actomyosin into actin and myosin; the Mg++-ATPose activity is correspondingly diminished (Barony and Joisle 1 BBA.,41,192,1960). PS, in conc. effective against muscle actomyosin, also decreases the Mg++-ATPase activity of brain preparations . We have isolated from bovine brain myosin-like and actin-like proteins which interact with each other, as well as with their counterparts isolated from muscle, with a resultant increase in viscosity. The addition of ATP(I0-4M) causes on abrupt decrease in the viscosity which increases again over a period of on hour. These studies further establish the presence in brain of a contractile actomyosin-like protei

Actomyosin-like protein isolated from mammalian brain / S. Puszkin, S. Berl, Columbia University, College of Physicians and Surgeons, New York 10032, Elena Puszkin, Mount Sinai School of Medicine, New York, D. D. Clarke, Fordham University, Bronx, New York

A protein with characteristics similar to actomyosin has been isolated from whole brain of rat and cat. It is soluble in 0.6 molar potassium chloride and insoluble in 0.1 1nolar potassium chloride. It superprecipitates with magnesium ions and adenosine triphosphate. It has adenosine triphosphatase activity stimulated by either 1nagnesium or calcium ions. Both superprecipitation and adenosine triphosphatase activity are inhibited by p-chloromercuribenzoate and Mersalyl but not by ouabai