Paschinger Katharina, Wilson Iain B H
Department für Chemie, Universität für Bodenkultur Wien, Wien 1190, Austria.
Department für Chemie, Universität für Bodenkultur Wien, Wien 1190, Austria
Glycobiology. 2015 Jun;25(6):585-90. doi: 10.1093/glycob/cwv015. Epub 2015 Mar 4.
N-Glycans from the nematode Haemonchus contortus (barber pole worm), a parasite of sheep and cattle, were the first to be described to possess up to three fucose residues associated with the N,N'-diacetylchitobiosyl core, two being on the reducing-terminal proximal GlcNAc and one on the distal core GlcNAc residue. The assumption was that truncated glycans from this organism with three hexose residues have the composition Man3GlcNAc2Fuc1-3. In this study, we have performed HPLC and MALDI-TOF MS/MS in combination with selected digestions of N-glycans from Haemonchus. A dominant trifucosylated Hex3HexNAc2Fuc3 glycan was modified not only with α1,6-fucose but also with a proximal core α1,3-fucose and a galactosylated distal α1,3-fucose; thereby, only two of the hexose residues were mannose. Other N-glycans displayed galactosylation of the core α1,6-fucose, antennal fucosylation or modification with phosphorylcholine. Thus, the N-glycans of Haemonchus contain a number of potentially immunogenic glycan epitopes also found in other parasites and our proposed structures are in line with the previously defined specificity of nematode glycosyltransferases as we show that distal fucosylation and the presence of an α1,6-mannose are apparently mutually exclusive. These data are thereby of importance for engineering cell lines capable of mimicking Haemonchus-type N-glycans in the preparation of recombinant proteins as vaccine candidates.
捻转血矛线虫（羊和牛的寄生虫）的 N -聚糖是首个被描述为在 N,N'-二乙酰壳二糖核心上带有多达三个岩藻糖残基的聚糖，其中两个位于还原端近端的 N -乙酰葡糖胺上，一个位于远端核心 N -乙酰葡糖胺残基上。当时的假设是，来自该生物体的具有三个己糖残基的截短聚糖的组成为 Man3GlcNAc2Fuc1 - 3。在本研究中，我们结合对捻转血矛线虫 N -聚糖的特定消化进行了高效液相色谱（HPLC）和基质辅助激光解吸电离飞行时间串联质谱（MALDI - TOF MS/MS）分析。一种主要的三岩藻糖基化 Hex3HexNAc2Fuc3 聚糖不仅被 α1,6 -岩藻糖修饰，还被近端核心 α1,3 -岩藻糖和半乳糖基化的远端 α1,3 -岩藻糖修饰；因此，只有两个己糖残基是甘露糖。其他 N -聚糖显示出核心 α1,6 -岩藻糖的半乳糖基化、触角岩藻糖基化或磷酸胆碱修饰。因此，捻转血矛线虫的 N -聚糖含有许多在其他寄生虫中也发现的潜在免疫原性聚糖表位，并且我们提出的结构与先前定义的线虫糖基转移酶的特异性一致，因为我们表明远端岩藻糖基化和 α1,6 -甘露糖的存在显然是相互排斥的。因此，这些数据对于构建能够在制备作为候选疫苗的重组蛋白时模拟捻转血矛线虫型 N -聚糖的细胞系具有重要意义。
