DiIulio N A, Bhavanandan V P
Department of Biochemistry and Molecular Biology, Milton S. Hershey Medical Center, Pennsylvania State University, Hershey 17033, USA.
Glycobiology. 1995 Mar;5(2):195-9. doi: 10.1093/glycob/5.2.195.
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.
用4 mM芳基 - N - 乙酰 - α - 半乳糖胺（一种糖蛋白O - 连接糖链延伸的抑制剂）处理H.Ep.2细胞，导致[3H]葡萄糖胺掺入表膜蛋白（一种MUC 1粘蛋白型糖蛋白）的量减少70 - 80%。从处理过的细胞提取物中免疫沉淀的部分糖基化表膜蛋白的凝胶电泳显示，在SDS - PAGE上有两条表观分子量分别为420和460 kDa的条带，而天然表膜蛋白的条带分子量为350和390 kDa。对部分糖基化表膜蛋白经β - 消除释放的糖类分析表明，存在大量的β1→3半乳糖基化和唾液酸化糖类。数据表明，芳基 - N - 乙酰 - α - 半乳糖胺对表膜蛋白中Ser/Thr连接的N - 乙酰半乳糖胺延伸的抑制只是部分抑制。
