Selective expression of different fucosylated epitopes on two distinct sets of Schistosoma mansoni cercarial O-glycans:: identification of a novel core type and Lewis X structure
Selective expression of different fucosylated epitopes on two distinct sets of Schistosoma mansoni cercarial O-glycans:: identification of a novel core type and Lewis X structure
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DOI：
10.1093/glycob/11.5.395
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发表时间：
2001-05-01
期刊：
影响因子：
4.3
通讯作者：
Khoo, KH
中科院分区：
文献类型：
--
作者：
Huang, HH;Tsai, PL;Khoo, KH
曼氏血吸虫的糖生物学主要由各种岩藻糖基化结构的发育调节表达所控制，最显著的是刘易斯X表位和多种形式的多岩藻糖基化序列Fuc α 1--> 2 Fuc α 1-->。对于感染性尾蚴阶段，刘易斯X已在总糖蛋白提取物的鞘糖脂和N-聚糖上被结构鉴定，并且发现多岩藻糖基化糖蛋白群体携带独特的末端序列，+/- Fuc α 1--> 2Fuc α 1--> [3GalNAc β 1-->4（Fuc α 1--> 2Fuc α 1--> 2Fuc α 1-->3）GlcNAc β 1--> 3Gal α 1-->]（n），在它们的O-聚糖上，通过连续的外切糖苷酶消化、高碘酸盐氧化和其他化学衍生，我们证明刘易斯X也可以在尾蚴O-聚糖上进行，但是两组独特的岩藻糖基化表位缀合到两种不同的核心结构上。发现刘易斯X、lacNAc或单个GlcNAc直接连接到--> 3Gal β 1--> 3GalNAc核心，并通过从还原末端GalNAc的C6分支出的另一个-β Gal残基间接连接，得到双触角样结构。因此表征的-->3（+/- Gal β 1-->6）Gal β 1-->3（--> 3Gal β 1-->6）GalNAc护理代表了O-聚糖的新核心类型。相反，先前表征的多岩藻糖基化末端序列在常规的1型和2型核心上进行。还原性释放的O-聚糖的最小结构定义为GalNAc β 1-> 4GlcNAc β 1-> 3Gal β 1-> 3GalNAcitol，其中总共2至4个岩藻糖连接至末端lacdiNAc，非还原性末端β-半乳糖基化GalNAc代替岩藻糖加帽导致另一个lacdiNAc单元的进一步延伸，该单元也可以直接从还原末端GalNAc的C6延伸并且类似地延长或终止。
The glycobiology of Schistosoma mansoni is dominated by developmentally regulated expression of various fucosylated structures, most notably the Lewis X epitope and a multifucosylated sequence, Fuc alpha1 --> 2Fuc alpha1 -->, in its various forms. For the infective cercarial stage, Lewis X has been structurally identified on glycosphingolipids and N-glycans of total glycoprotein extracts, and a population of multifucosylated glycoproteins were found to carry a unique terminal sequence, +/- Fuc alpha1 --> 2Fuc alpha1 --> [3GalNAc beta1 -->4(Fuc alpha1 --> 2Fuc alpha1 --> 2Fuc alpha1 -->3)GlcNAc beta1 --> 3Gal alpha1 -->](n), on their O-glycans, Using a mass spectrometry approach coupled with chromatographic separation, sequential exoglycosidase digestion, periodate oxidation, and other chemical derivatization, we demonstrate that Lewis X could also be carried on the cercarial O-glycans, but the two distinctive sets of fucosylated epitopes were conjugated to two different core structures. Lewis X, lacNAc, or single GlcNAc was found to attach directly to the --> 3Gal beta1 --> 3GalNAc core and indirectly via another -beta Gal residue branching off from C6 of the reducing end GalNAc to give a biantennary-like structure. The -->3(+/- Gal beta1 -->6)Gal beta1 -->3(--> 3Gal beta1 -->6)GalNAc care thus characterized represents a novel core type for O-glycans, In contrast, the previously characterized multifucosylated terminal sequences were carried on conventional type 1 and 2 cores. The smallest structures of the reductively released O-glycans were defined as GalNAc beta1 --> 4GlcNAc beta1 --> 3Gal beta1 --> 3GalNAcitol with a total of two to four fucoses attached to the terminal lacdiNAc, alpha -Galactosylation of the nonreducing terminal beta -GalNAc instead of fucose capping leads to further elongation with another lacdiNAc unit that could also extend directly from C6 of the reducing end GalNAc and similarly elongated or terminated.