Isolation and characterization of two oncofetal glycoproteins from hamster pancreas using concanavalin A and preparative electrophoresis

Pancreatic fetal acinar antigens in the Syrian golden hamster, which are associated with development of the pancreas, have been previously described. In this study, two major antigens were isolated from fetal pancreas using affinity chromatography on Con A-Sepharose and preparative electrophoresis. Homogenates from fetal and adult pancreas were analyzed for their ability to bind to concanavalin A. This lectin allowed obtention of eluted fractions accounting for 2 and 0.7%, respectively, of the protein content in crude extracts. Concanavalin A-positive fraction from fetal pancreas contained two major carbohydrate-reactive glycoproteins of relative molecular weight (Mr) 80 000 and 58 000 in SDS-polyacrylamide gel electrophoresis. Both behaved as fetal antigens in nitrocellulose blot immunoassay. Similar experiments with chemically induced tumors of the pancreas led to a concanavalin A fraction containing the 80 and 58 kDa fetal glycoproteins; but in this case, the fraction was quite heterogeneous. Our data provide new support for the existence of differentiation antigens in the acinar cells of the pancreas, and indicate that two major ones are glycoproteins. Moreover, both are expressed in pancreatic tumors.