Akiyama K, Simons E R, Bernasconi P, Schmid K, van Halbeek H, Vliegenthart J F, Haupt H, Schwick H G
J Biol Chem. 1984 Jun 10;259(11):7151-4.
Human plasma galactoglycoprotein (Mr = 81,000) which was recently identified and characterized (Schmid, K., Mao, S. K. Y., Kimura, A., Hayashi, S., and Binette , J. P. (1980) J. Biol. Chem. 255, 3221-3226) was found to possess an unusually high carbohydrate content (76%) comprised of NeuAc, Gal, Man, Fuc, GalNAc, and GlcNAc. The aim of the present investigation was to elucidate the primary structure of the oligosaccharide units of this protein. For the study of the O-glycosidic oligosaccharide chains, the protein was subjected to beta-elimination and the resulting oligosaccharide preparations were analyzed by 500-MHz 1H NMR spectroscopy. The structure of the predominant glycan, a hexasaccharide: (formula; see text) and that of a tetrasaccharide: NeuAc alpha(2----3)Gal beta(1----3)[NeuAc alpha (2----6)]GalNAc-ol, were determined. The protein possesses approximately 40 hexasaccharides and 3 tetrasaccharides/mol. For the isolation of its N-glycosidic oligosaccharide chains, the protein was exhaustively digested with proteases followed by chromatography of the desialyzed resulting glycopeptide fraction on concanavalin A-Sepharose. 500-MHz 1H NMR spectroscopy of the obtained preparations revealed the presence of 3 diantennary N-glycosidic chains that are extended with a Fuc residue at the Asn-linked GlcNAc.
最近被鉴定和表征的人血浆半乳糖糖蛋白（相对分子质量=81,000）（施密德，K.，毛，S.K.Y.，木村，A.，林，S.，和比内特，J.P.（1980）《生物化学杂志》255，3221 - 3226）被发现具有异常高的碳水化合物含量（76%），其由唾液酸、半乳糖、甘露糖、岩藻糖、N - 乙酰半乳糖胺和N - 乙酰葡糖胺组成。本研究的目的是阐明该蛋白质寡糖单元的一级结构。为了研究O - 糖苷寡糖链，该蛋白质进行了β - 消除反应，所得的寡糖制剂通过500兆赫的1H核磁共振光谱进行分析。确定了主要聚糖的结构，一种六糖：（分子式；见正文）以及一种四糖的结构：唾液酸α(2→3)半乳糖β(1→3)[唾液酸α(2→6)]N - 乙酰半乳糖胺 - 醇。该蛋白质每摩尔约含有40个六糖和3个四糖。为了分离其N - 糖苷寡糖链，该蛋白质用蛋白酶进行了彻底消化，然后将去唾液酸化后的所得糖肽部分在伴刀豆球蛋白A - 琼脂糖上进行色谱分析。对所得制剂进行的500兆赫1H核磁共振光谱显示存在3条双天线N - 糖苷链，它们在与天冬酰胺连接的N - 乙酰葡糖胺处延伸有一个岩藻糖残基。
