Trypsin treatment which elicits DNA sythesis, removes a high molecular weight glycoprotein from the plasma membrane of sea urchin embryonic cells.

SDS-polyacrylamide gel electrophoresis of plasma membrane proteins from sea urchin embryos at the swimming blastula stage allows the identification of fifteen-seventeen components, five of which are glycoproteins. One of these (molecular weight about 145,000) is almost completely absent in the plasma membrane of trypsin treated cells.