Hemocyanin from the keyhole limpet Megathura crenulata (KLH) carries a novel type of N-glycans with Gal(β1-6)Man-motifs
Hemocyanin from the keyhole limpet Megathura crenulata (KLH) carries a novel type of N-glycans with Gal(β1-6)Man-motifs
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DOI：
10.1046/j.1432-1033.2002.03244.x
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发表时间：
2002-11-01
期刊：
影响因子：
--
通讯作者：
Geyer, R
中科院分区：
文献类型：
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作者：
Kurokawa, T;Wuhrer, M;Geyer, R
匙孔血蓝蛋白（KLH）是一种细胞外呼吸蛋白，广泛用作半抗原载体和免疫刺激剂。尽管人们普遍认为这种糖蛋白的糖成分可能与KLH的抗原性和生物医学特性有关，但对其碳水化合物结构的了解仍然有限。因此，我们研究了KLH的N-连接寡糖。从胰蛋白酶糖肽中酶促释放聚糖链，吡啶胺化并通过二维HPLC分离。通过糖组成和甲基化分析、MALDI-TOF-MS、ESI-离子阱-MS和连续外切糖苷酶消化，仅获得中性寡糖并对其进行表征。结果表明，KLH携带高甘露糖型聚糖及其衍生的截短糖链。作为一个特征，许多他研究的N-聚糖含有Gal（beta1-6）Man单元，迄今为止在糖蛋白-N-聚糖中还没有发现。因此，我们的研究表明，他的海洋软体动物糖蛋白的特点是由一个独特的寡糖模式，包括部分，新的结构元件。
Keyhole limpet (Megathura crenulata) hemocyanin (KLH), an extracellular respiratory protein, is widely used as hapten carrier and immune stimulant. Although it is generally accepted hat he sugar constituents of this glycoprotein are likely to be implicated in the antigenicity and biomedical properties of KLH, knowledge of its carbohydrate structure is still limited. Therefore, we have investigated the N-linked oligosaccharides of KLH. Glycan chains were enzymatically liberated from tryptic glycopeptides, pyridylaminated and separated by two-dimensional HPLC. Only neutral oligosaccharides were obtained and characterized by carbohydrate constituent and methylation analyses, MALDI-TOF-MS, ESI-ion trap-MS and sequential exoglycosidase digestion. The results revealed that KLH is carrying high mannose-type glycans and truncated sugar chains derived thereof. As a characteristic feature, a number of he studied N-glycans contained a Gal(beta1-6) Man-unit which has not been found in glycoprotein-N-glycans so far. Hence, our studies demonstrate hat his marine mollusk glycoprotein is characterized by a unique oligosaccharide pattern comprising, in part, novel structural elements.