Electrophoretic characterization of the protein and glycoprotein content of purified Kurloff cell cytosol.

Proteins and glycoproteins from Kurloff cells (KC) were analyzed by SDS-polyacrylamide electrophoresis, isoelectric focusing, and two-dimensional electrophoresis, and major cytosolic glycoproteins of Mr 30,000-35,000 and pHi 5.7-6.7 were characterized. After incubation with radiolabeled amino acids (L-35S) methionine and L-(U14C) leucine) and gel autoradiography, all the proteins seemed to be labeled. D-(U14C) glucosamine-labeled proteins and periodic-acid-Schiff(PAS)-positive proteins focalized at the same pH. These data suggest that the major glycoprotein are synthesized by the KC themselves and that the PAS-positive Kurloff body has an endogenous origin. Whereas estrogens increase the KC number, 10(-6) M estradiol had no effect on the KC protein electrophoretic pattern and protein biosynthesis, in agreement with the lack of estradiol receptor in the KC cytosol.