Kamada Y, Muramatsu H, Kawata M, Takamizawa H, Muramatsu T
Department of Biochemistry, Faculty of Medicine, Kagoshima University.
J Biochem. 1988 Nov;104(5):738-41. doi: 10.1093/oxfordjournals.jbchem.a122543.
Poly-N-acetyllactosamines were prepared from Ehrlich carcinoma cells cultured in the presence of [14C]galactose. Methylation analysis indicated that 31% of the galactose was in the non-reducing end. Of it, 77% was cleaved by alpha-galactosidase, and 56% was released as a disaccharide by endo-beta-galactosidase C. Methylation analysis confirmed that the released disaccharide was mostly Gal alpha 1----3Gal. Therefore, Gal alpha 1----3Gal structure, not Gal alpha 1----3(Gal alpha 1----6)Gal structure, was the major alpha-galactosyl structure in the poly-N-acetyllactosamines synthesized. Furthermore, alpha-galactosidase digestion did not change the content of disubstituted galactosyl residues. Thus, Gal alpha 1----3(Gal alpha 1----6)Gal structure, which was suggested to be the sole non-reducing terminal structure of poly-N-acetyllactosamines of Ehrlich carcinoma cells, was not detected in significant amounts under the present experimental conditions.
多聚-N-乙酰乳糖胺是由在[14C]半乳糖存在下培养的艾氏腹水癌细胞制备的。甲基化分析表明，31%的半乳糖位于非还原端。其中，77%被α-半乳糖苷酶切割，56%被内切β-半乳糖苷酶C释放为二糖。甲基化分析证实，释放的二糖主要是Galα1----3Gal。因此，Galα1----3Gal结构而非Galα1----3（Galα1----6）Gal结构是合成的多聚-N-乙酰乳糖胺中的主要α-半乳糖基结构。此外，α-半乳糖苷酶消化并未改变双取代半乳糖基残基的含量。因此，在目前的实验条件下，未检测到大量被认为是艾氏腹水癌细胞多聚-N-乙酰乳糖胺唯一非还原末端结构的Galα1----3（Galα1----6）Gal结构。
