Abstract
A study was made on the superprecipitation of carp myosin B by measuring the change in turbidity induced by addition of ATP.
On addition of 0.2-0.4mm ATP, carp myosin B suspension in a medium containing 80-100mM KCl, 1mM MgCl2, 0.1mM CaCl2, 0.2-0.4mg/ml of myosin B, and 25mM Tris-maleate (pH 7.0), showed a typical change in turbidity at 25°C; that is, an early instant decrease for some time (clearing phase), followed by a rapid large increase leading to the maximum.
The turbidity changes, induced under above conditions, are favourable for estimation of superprecipitation of carp myosin B. The rate of superprecipitation was then demonstrated as the reciprocal value of the time required for half-maximal change in turbidity (t1/2)-1. It was thus found that (t1/2)-1 and turbidity change were in linear relations when the protein concentra-tion is lower than the approximate of 0.4mg/ml.
