Nomura K, Nakajo N, Hidari K I, Nomura H, Murata M, Suzuki M, Yamana K, Hirabayashi Y
Department of Biology, Faculty of Science, Kyushu University, Fukuoka, Japan.
Biochem J. 1995 Mar 15;306 ( Pt 3)(Pt 3):821-7. doi: 10.1042/bj3060821.
For understanding of the biological function of glycoconjugates during embryogenesis and morphogenesis, Xenopus laevis is considered a very useful animal model. We have found that blood-group-active molecules characteristically were distributed in the cell-cell contact region of Xenopus blastula cells. The chemical nature of blood-group-active glycoconjugates, including glycosphingolipids, is little known. T.l.c.-immunostaining using anti-blood-group-antigen antibodies showed that many species of blood group-B-active glycosphingolipids existed in the neutral glycosphingolipid fraction extracted from Xenopus laevis eggs. Among the B-active glycosphingolipids detected, two major components with the fastest mobility on a t.l.c. plate, tentatively termed XN-1 and XN-2, were isolated, and their chemical structures were characterized by gas chromatography-mass spectrometry, immunological anlaysis, fast-atom-bombardment mass spectrometry and 1H-n.m.r. spectroscopy. Both XN-1 and XN-2 had an identical pentaoligosaccharide structure, but differed in their ceramide moiety. The chemical structure is: [table: see text]. This is a novel type of pentaglycosylceramide with blood-group B activity, in that it lacks N-acetylhexosamine in its core carbohydrate structure. In this paper, a possible involvement of the blood-group antigen in the cell-adhesion process of Xenopus embryonic cells is discussed.
为了解糖缀合物在胚胎发生和形态发生过程中的生物学功能，非洲爪蟾被认为是一种非常有用的动物模型。我们发现，具有血型活性的分子特征性地分布在非洲爪蟾囊胚细胞的细胞间接触区域。包括糖鞘脂在内的具有血型活性的糖缀合物的化学性质鲜为人知。使用抗血型抗原抗体的薄层层析免疫染色显示，从非洲爪蟾卵中提取的中性糖鞘脂部分存在多种B血型活性糖鞘脂。在检测到的B活性糖鞘脂中，分离出了在薄层层析板上迁移速度最快的两种主要成分，暂称为XN-1和XN-2，并通过气相色谱-质谱、免疫分析、快原子轰击质谱和1H核磁共振光谱对其化学结构进行了表征。XN-1和XN-2都具有相同的戊寡糖结构，但神经酰胺部分不同。化学结构为：[表格：见原文]。这是一种具有B血型活性的新型五糖基神经酰胺，其核心碳水化合物结构中缺乏N-乙酰己糖胺。本文讨论了血型抗原在非洲爪蟾胚胎细胞黏附过程中的可能作用。
