STRUCTURAL BASIS OF DIFFERENT AFFINITIES OF 2 TYPES OF ACIDIC N-GLYCOSIDIC GLYCOPEPTIDES FOR CONCANAVALIN-A-SEPHAROSE
STRUCTURAL BASIS OF DIFFERENT AFFINITIES OF 2 TYPES OF ACIDIC N-GLYCOSIDIC GLYCOPEPTIDES FOR CONCANAVALIN-A-SEPHAROSE
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DOI：
10.1016/0014-5793(76)80911-8
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发表时间：
1976-01-01
期刊：
影响因子：
3.5
通讯作者：
RAUVALA, H
中科院分区：
文献类型：
--
作者：
KRUSIUS, T;FINNE, J;RAUVALA, H
亲和层析是分离纯化糖肽和糖蛋白的有效手段。最常用的凝集素是刀豆蛋白A。对寡糖和糖肽与该凝集素结合的研究表明，至少需要两个非取代或2-O-取代的甘露糖醇残基[L]。最近关于不同来源的糖肽的分离报道表明，除了中性的富含甘露糖的糖肽外，一些酸性N-糖苷糖肽还与凝集素结合，而另一些则不是[2-S]。由于两种酸性糖肽的碳水化合物组成相当相似[3-S]，亲和力不同的原因尚不清楚。本研究的目的是研究刀豆蛋白A-琼脂糖凝胶分离酸性N-糖苷糖肽的结构基础。已知(或部分已知)结构的糖肽在刀豆蛋白A上进行层析，结合和不结合凝集素的部分通过甲基化进行分析。发现具有两个外围NeuNAc-Gal-GlcNAc*-支链与核心五糖相连的糖肽与凝集素结合，而具有三个支链的糖肽则不结合(这些化合物的结构如下所示)。不同的缩写：NcwVAc，N-乙酰神经氨酸；GluVAc，N-乙酰氨基葡萄糖；Gal，半乳糖；Man，甘露糖；ASN，天冬酰胺
Affinity chromatography on lectins covalently bound to Sepharose has proved to be a useful tool for the fractionation and purification of glycopeptides and glycoproteins. The most commonly used lectin for this purpose has been concanavalin A. Studies on the binding of oligosaccharides and glycopeptides to this lectin have indicated that at least two nonsubstituted or 2-O-substituted ol-mannosyl residues are required [l]. Recent reports on the fractionation of glycopeptides from various source: on; oncanavaIin A-Sepharose have shown that in addition to the neutral mannose-rich glycopeptides, some acidic N-glycosidic glycopeptides are bound by the lectin, whereas others are not [2-S]. Since the carbohydrate composition of both types of acidic glycopeptides is rather similar [3--S], the reason for the difference in affinity is not understood. The purpose of the present investigation was to study the structural basis of the separation of acidic N-glycosidic glycopeptides on concanavalin A-Sepharose. Glycopeptides with known (or partially known) structures were chromatographed on concanavalin A and fractions bound and not bound by the lectin were analyzed by methylation. It was found that glycopeptides possessing two peripheral NeuNAc-Gal-GlcNAc*-branches linked to the core pentasaccharide were bound by the lectin, whereas glycopeptides with three branches were not (the structures of these compounds are shown below). The differentAbbreviations: NcwVAc, N-acetylneuraminic acid; GluVAc, N-acetylglucosamine; Gal, galactose; Man, mannose; Asn, asparagine