The saccharides of the MUC 1 mucin-type glycoprotein, epitectin, produced by H.Ep.2 cells in the presence of aryl-N-acetyl-alpha-galactosaminides.
The treatment of H.Ep.2 cells with 4 mM aryl-N-acetyl-alpha-galactosaminide, an inhibitor of the elongation of O-linked saccharides of glycoproteins, resulted in a 70-80% decrease in the incorporation of [3H]glucosamine into epitectin (a MUC 1 mucin-type glycoprotein). Gel electrophoresis of the partially glycosylated epitectin immunoprecipitated from the extracts of treated cells showed two bands of apparent mol. wts 420 and 460 kDa on SDS-PAGE, compared to bands of 350 and 390 kDa for the native epitectin. Analysis of the saccharides released by beta-elimination from the partially glycosylated epitectin showed the presence of substantial levels of beta 1-->3 galactosylated and sialylated saccharides. The data indicate that the inhibition of elongation of Ser/Thr-linked N-acetyl-galactosamine in epitectin by aryl-N-acetyl-alpha-galactosaminides is only partial.
DiIulio
N A
NA
Department of Biochemistry and Molecular Biology, Milton S. Hershey Medical Center, Pennsylvania State University, Hershey 17033, USA.
Bhavanandan
V P
VP
D000116:Acetylgalactosamine / Q000031:analogs & derivatives* / Q000494:pharmacology*; D015295:Antigens, Tumor-Associated, Carbohydrate / Q000096:biosynthesis* / Q000737:chemistry* / Q000302:isolation & purification; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002460:Cell Line; D004591:Electrophoresis, Polyacrylamide Gel; D005434:Flow Cytometry; D005944:Glucosamine / Q000378:metabolism; D006801:Humans; D007822:Laryngeal Neoplasms; D008562:Membrane Glycoproteins / Q000737:chemistry*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D018396:Mucin-1; D009077:Mucins / Q000737:chemistry*; D009363:Neoplasm Proteins / Q000096:biosynthesis / Q000737:chemistry; D009844:Oligosaccharides / Q000737:chemistry* / Q000302:isolation & purification; D012694:Serine; D013912:Threonine / Q000378:metabolism; D014316:Tritium; D014407:Tumor Cells, Cultured
D015295:Antigens, Tumor-Associated, Carbohydrate; D008562:Membrane Glycoproteins; D018396:Mucin-1; D009077:Mucins; D009363:Neoplasm Proteins; D009844:Oligosaccharides; D014316:Tritium; D013912:Threonine; D012694:Serine; D000116:Acetylgalactosamine; D005944:Glucosamine