The distribution of phosphoprotein phosphatase (PPPase) and estrogen-induced protein (IP) from 19- to 20-day-old rat uteri before and after fractionation of uterine cytosol, by ammonium sulfate, and by preparative cellulose acetate gel electrophoresis was studied. There was a lack of significant difference between the specific activity of PPPase or its electrophoretic mobility in control extracts and those of extracts made 1 hour after injection of the rats with 5 mcg estradiol-17beta. Most of the recovered PPPase activity appeared in the fraction precipitating between 0-50% saturation with ammonium sulfate. Most of the IP is found at 50-80% saturation, and less than 10% of the PPPase activity. A single peak of PPPase activity was shown at a mobility of .5 relative to bovine serum albumin with electrophoresis of the 50-80% ammonium sulfate fraction. A peak of IP with mobility of 1.2 was also shown. ''The results are incompatible with the view that IP mediates estrogen action by virtue of its PPPase activity.''.
|Number of pages||1|
|Journal||Israel Journal of Medical Sciences|
|State||Published - Nov 1975|