Heterogeneity of carcinoembryonic antigen. I. Concanavalin A-reactive and -nonreactive CEA.
The use of Con A-Sepharose affinity chromatography for preparation of CEA from two metastatic liver tumors resulted in a separation of two species of CEA. One is concanavalin A-reactive CEA (CEA-M): the other is Con A-nonreactive CEA (CEA-P). Both CEA-M and CEA-P were glycoproteins and have identical antigenicity. However, 4 samples of CEA-M and CEA-P subfractions differed in their protein:carbohydrate ratios. The yield of CEA-M was greater than that of CEA-P. In electrophoresis, both CEA-M and CEA-P migrated at the region of beta-globulin of human blood serum. The isoelectric points of 4 samples of CEA-M and CEA-P subfractions from two different tumor sources differed from each other. In these preparations CEA-M usually showed a larger value of isoelectric point than CEA-P. Ultracentrifugal analysis of these four preparations revealed only a single peak, except CEA-P in case 1. Antigenic activity of CEA-M was almost completely destroyed by beta-N-acetylhexosaminidase treatment but only partly digestion with pronase. A possibility was suggested that N-acetylglucosamine at nonreducing terminal(s) is essential for the antigenic determinant groups of CEA molecule.
D001665:Binding Sites; D002241:Carbohydrates; D002272:Carcinoembryonic Antigen / Q000032:analysis; D002846:Chromatography, Affinity; D003208:Concanavalin A; D006595:Hexosamines / Q000032:analysis; D006801:Humans; D005779:Immunodiffusion; D007122:Immunoelectrophoresis; D008113:Liver Neoplasms / Q000276:immunology; D008970:Molecular Weight; D009362:Neoplasm Metastasis; D010190:Pancreatic Neoplasms / Q000276:immunology; D011485:Protein Binding; D012004:Rectal Neoplasms / Q000276:immunology
D002241:Carbohydrates; D002272:Carcinoembryonic Antigen; D006595:Hexosamines; D003208:Concanavalin A