The nematode Caenorhabditis elegans synthesizes unusual O-linked glycans:: identification of glucose-substituted mucin-type O-glycans and short chondroitin-like oligosaccharides
The nematode Caenorhabditis elegans synthesizes unusual O-linked glycans:: identification of glucose-substituted mucin-type O-glycans and short chondroitin-like oligosaccharides
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DOI：
10.1042/0264-6021:3570167
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发表时间：
2001-07-01
影响因子：
4.1
通讯作者：
Strecker, G
中科院分区：
文献类型：
--
作者：
Guérardel, Y;Balanzino, L;Strecker, G
秀丽隐杆线虫是研究多细胞生物发育过程中糖复合物作用的相关模型。已经分离出几种编码参与N-和O-连接聚糖合成的糖基转移酶的基因，但是，除了糖胺聚糖的重复二聚体之外，迄今为止还没有发表任何类型组分的详细结构。本研究的目的是建立C. Elegans，以深入了解这种生物体中表达的内源性糖基转移酶活性。通过NMR和MS的分析，我们确定了其中7个具有特殊结构的组分的序列，它们中的大多数都是以（β 1 -4）Glc和（β 1 -6）Glc残基取代Gal和/或GalNAc的1型核心为特征的。另一种化合物在末端位置显示GalNAc（β 1 -4）N-乙酰葡糖胺醇序列，其上连接有被Fuc和2-O-甲基-岩藻糖残基取代的β-Gal四聚体。我们的实验程序也导致分离的糖胺聚糖样成分酸性寡甘露糖基型N-聚糖。特别是，数据证实了C。elegans合成普遍存在的接头序列GlcA（β 1 -3）Gal（β 1 - 3）Gal（β 1 -4）Xyl。
The free-living nematode Caenorhabditis elegans is a relevant model for studies on the role of glycoconjugates during development of multicellular organisms. Several genes coding for glycosyltransferases involved in the synthesis of N- and O-linked glycans have already been isolated, but, apart from repetitive dimers of glycosaminoglycans, no detailed structure of either type of component has been published so far. This study aimed to establish the structures of the major O-glycans synthesized by C. Elegans to give an insight into the endogenous glycosyltransferase activities expressed in this organism. By the use of NMR and MS, we have resolved the sequence of seven of these components that present very unusual features, Most of them were characterized by the type-1 core substituted on Gal and/or GalNAc by (beta1-4)Glc and (beta1-6)Glc residues. Another compound exhibited the GalNAc(beta1-4)N-acetylglucosaminitol sequence in the terminal position, to which was attached a tetramer of beta -Gal substituted by both Fuc and 2-O-methyl-fucose residues. Our experimental procedure led also to the isolation of glycosaminoglycan-like components acid oligomannosyl-type N-glycans. In particular, the data confirmed that C. elegans synthesizes the ubiquitous linker sequence GlcA(beta1-3)Gal(beta1-3)Gal(beta1-4)Xyl.