Bierhuizen M F, Hansson M, Odin P, Debray H, Obrink B, van Dijk W
Department of Medical Chemistry, Faculty of Medicine, Vrije Universiteit, Amsterdam, The Netherlands.
Glycoconj J. 1989;6(2):195-208. doi: 10.1007/BF01050648.
The N-linked oligosaccharides of cell-CAM 105, a glycoprotein involved in the intercellular adhesion between rat hepatocytes, were studied by sequential lectin-agarose affinity chromatography of desialylated, [14C]-labelled glycopeptides. These glycopeptides were obtained by extensive pronase digestion followed by N-[14C]acetylation of the peptide moieties and desialylation by mild acid hydrolysis. Assuming that all glycopeptides were radiolabelled to the same specific radioactivity, Concanavalin A-Sepharose chromatography indicated that the majority of the glycans (84%) were of the complex-type of which approximately half were bi-antennary structures. The remainder of the glycans comprised oligomannose-type structures and/or incomplete bi-antennary structures. Pisum sativum lectin-agarose chromatography revealed that part of the bi-antennary glycans contained a fucose residue alpha(1-6)-linked to the N-acetylglucosamine which is attached to asparagine. Furthermore, the presence of tri-, and tetra- and/or tri'-antennary complex-type glycans was demonstrated by chromatography on immobilized Phaseolus vulgaris leukoagglutinating phytohemagglutinin and Aleuria aurantia lectin (AAL). AAL-agarose chromatography furthermore indicated the presence of alpha(1-3)-linked fucose in part of these glycopeptides, whereas no alpha(1-6)-linked fucose could be detected in these structures. The degree of beta-galactosylation of the complex-type glycans was investigated by chromatography on Ricinus communis agglutinin-agarose. The results indicated that only part of the bi-antennary glycans were completely beta-galactosylated. Similarly, at least three beta-galactose residues were present in only a part of the tri-, and tetra- and/or tri'-antennary glycans.
细胞黏附分子105（cell-CAM 105）是一种参与大鼠肝细胞间黏附的糖蛋白，其N-连接寡糖通过对去唾液酸化的、[14C]标记的糖肽进行连续的凝集素-琼脂糖亲和层析进行研究。这些糖肽通过广泛的链霉蛋白酶消化获得，随后对肽部分进行N-[14C]乙酰化，并通过温和酸水解进行去唾液酸化。假设所有糖肽都被标记到相同的比放射性，伴刀豆球蛋白A-琼脂糖层析表明，大多数聚糖（84%）是复合型的，其中约一半是双天线结构。其余的聚糖包括寡甘露糖型结构和/或不完全的双天线结构。豌豆凝集素-琼脂糖层析显示，部分双天线聚糖含有一个与连接到天冬酰胺的N-乙酰葡糖胺α(1-6)连接的岩藻糖残基。此外，通过固定化菜豆白细胞凝集素植物血凝素和橙黄银耳凝集素（AAL）层析证明了三天线、四天线和/或三'天线复合型聚糖的存在。AAL-琼脂糖层析还表明，部分这些糖肽中存在α(1-3)连接的岩藻糖，而在这些结构中未检测到α(1-6)连接的岩藻糖。通过蓖麻凝集素-琼脂糖层析研究了复合型聚糖的β-半乳糖基化程度。结果表明，只有部分双天线聚糖完全β-半乳糖基化。同样，至少三个β-半乳糖残基仅存在于部分三天线、四天线和/或三'天线聚糖中。
