ALPHA-(2-]3)- AND ALPHA-(2-]6)-SIALYLTRANSFERASE ACTIVITIES PRESENT IN 3 VARIANTS OF EHRLICH TUMOR-CELLS - IDENTIFICATION OF THE PRODUCTS DERIVED FROM N-ACETYLLACTOSAMINE AND BETA-D-GAL-(1-]3)-ALPHA-D-GALNAC-(1-]O)-BN

We compared several sialyltransferase activities related to synthesis of O-linked and N-linked sialylglycoproteins in Ehrlich ascites tumor cells that grow normally in murine ascites, but are not adherent nor g row in tissue culture (na-EAT cells),with those in cells that were sel ected to grow in tissue culture and adhere to extracellular matrices ( a-EAT cells). Crude Golgi preparations from both cell types contained predominantly beta-D-Gal-(1-->3)-D-GalNAc alpha-(2-->3) -sialyltransfe rase activity. Sialylation of N-acetyllactosamine, lacto-N-tetraose, a nd benzyl alpha-D-GalNAc occurred at from 1 to 4% of that activity. An alysis, by ion-exchange HPLC at high pH, of sialylated N-acetyllactosa mine showed that na-EAT cells sialylated beta-D-Gal-(1-->4)-D-GlcNAc m ostly by alpha-(2-->3)-sialyltransferase, whereas beta-D-Gal-(1-->4)-D -GlcNAc alpha-(2 -->6) -sialyltransferase activity was prominent in a- EAT cells. In addition, preparations from na-EAT cells formed signific ant quantities of an unknown tritiated product from CMP-[9-H-3]sialic acid, suggesting at least one other difference in enzyme levels betwee n the cell types. a-EAT cells reestablished in murine ascites for 11 p assages retained the sialyltransferase levels characteristic of a-EAT cells. When viable cells were labeled with D-[H-3] glucosamine, na-EAT cells formed larger amounts of sialic acid in O-linked glycoproteins than did a-EAT cells.