Green E D, van Halbeek H, Boime I, Baenziger J U
J Biol Chem. 1985 Dec 15;260(29):15623-30.
The Asn-linked oligosaccharides of the pituitary hormone lutropin (LH) contain both sulfate and GalNAc. Bovine pituitary explants incorporate [3H]glucosamine, [3H]mannose, [3H]fucose, and [35S]sulfate into the Asn-linked oligosaccharides of LH. Endoglycosidase F or N-glycanase releases the [3H]glucosamine- and [3H]mannose-labeled oligosaccharides from the protein, which resolve on anion-exchange high pressure liquid chromatography as neutral (S-0), mono- (S-1), and disulfated (S-2) species. Based on sequential enzyme digestion, methylation, periodate oxidation, and nuclear magnetic resonance studies, the proposed structure for S-2 is as follows: formula see text. Sulfate is confined to position 3 or 4 of GalNAc based on periodate and methylation data and can be removed by methanolysis. The presence of beta-linked GalNAc at a position typically occupied by Gal has not previously been observed.
垂体激素促黄体生成素（LH）的天冬酰胺连接型寡糖同时含有硫酸酯和N-乙酰半乳糖胺（GalNAc）。牛垂体外植体将[3H]葡糖胺、[3H]甘露糖、[3H]岩藻糖和[35S]硫酸酯掺入LH的天冬酰胺连接型寡糖中。内切糖苷酶F或N-聚糖酶从蛋白质上释放出[3H]葡糖胺和[3H]甘露糖标记的寡糖，这些寡糖在阴离子交换高压液相色谱上分离为中性（S-0）、单硫酸化（S-1）和双硫酸化（S-2）种类。基于顺序酶切、甲基化、高碘酸盐氧化和核磁共振研究，S-2的推测结构如下：分子式见正文。根据高碘酸盐和甲基化数据，硫酸酯局限于GalNAc的3位或4位，并且可以通过甲醇解去除。以前尚未观察到在通常由Gal占据的位置存在β连接的GalNAc。
