Woodward H D, Ringler N J, Selvakumar R, Simet I M, Bhavanandan V P, Davidson E A
Department of Biological Chemistry, Milton S. Hershey Medical Center, Pennsylvania State University, Hershey 17033.
Biochemistry. 1987 Aug 25;26(17):5315-22. doi: 10.1021/bi00391a015.
Following several model experiments, conditions were developed for optimal deglycosylation of tracheal mucin glycoproteins. Exposure of rigorously dried material to trifluoromethanesulfonic acid at 0 degree C for up to 8 h results in cleavage of essentially all fucose, galactose, and N-acetylglucosamine, about 80% of the N-acetylneuraminic acid (NeuNAc), and a variable amount of N-acetylgalactosamine (GalNAc), the sugar involved in linkage to protein. Residual N-acetylneuraminic acid is sialidase susceptible and apparently in disaccharide units, presumably NeuNAc2----GalNAc. The remaining N-acetylgalactosamine is mostly present as monosaccharides, and a few Gal beta 1----3GalNAc alpha units are also present; both are cleaved by appropriate enzymatic treatment. The saccharide-free proteins obtained from either human or canine mucin glycoproteins have molecular weights of about 100,000 and require chaotropic agents or detergents for effective solubilization.
经过多次模型实验，确定了气管粘蛋白糖蛋白最佳去糖基化的条件。将经过严格干燥的材料在0℃下暴露于三氟甲磺酸中长达8小时，基本上所有的岩藻糖、半乳糖和N-乙酰葡糖胺、约80%的N-乙酰神经氨酸（NeuNAc）以及可变数量的与蛋白质连接的糖N-乙酰半乳糖胺（GalNAc）都会被裂解。残留的N-乙酰神经氨酸对唾液酸酶敏感，显然以二糖单位形式存在，推测为NeuNAc2----GalNAc。其余的N-乙酰半乳糖胺大多以单糖形式存在，也存在一些Galβ1----3GalNAcα单位；两者都可通过适当的酶处理裂解。从人或犬粘蛋白糖蛋白中获得的无糖蛋白分子量约为100,000，需要离液剂或去污剂才能有效溶解。
