Conformation of the oligosaccharide chain of GM1 ganglioside in a carbohydrate-enriched surface
Conformation of the oligosaccharide chain of GM1 ganglioside in a carbohydrate-enriched surface
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DOI：
10.1016/s0006-3495(98)77788-4
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发表时间：
1998-01-01
影响因子：
3.4
通讯作者：
Sonnino, S
中科院分区：
文献类型：
--
作者：
Brocca, P;Berthault, P;Sonnino, S
用高分辨H-1-NMR研究了102-kDa脂质修饰的-G（M1）胶束表面神经节苷脂G（M1）碳水化合物部分的溶液结构。胶束表面可以被认为是神经节苷脂的簇状横向分布，每个单体被锚定在富含碳水化合物的模型膜基质中。在短混合时间下的H-1 NOESY测量揭示了刚性三糖核心-β-GalNAc-（1-4）-[α-Neu 5Ac-（2-3）]-β-Gal-和更柔性的β-Gal-（1-3）-β-GalNAc-末端糖苷键。在脂质修饰的G（M1）神经节苷脂胶束系统中，没有证据表明分子间的并排碳水化合物相互作用调节或以任何方式改变头基空间排列。可能的单体间的相互作用在支链三糖部分的水平上进行了进一步研究的混合胶束的天然N-羟乙酰基-和N-乙酰神经氨酸含有G（M1）在D2 O，利用不同的NMR功能的N-羟乙酰基-和N-乙酰神经氨酸，这使得唾液酸环质子信号之间的歧视。水/神经节苷脂-OH质子化学交换率的测量表明羟基参与在8位唾液酸在强分子内相互作用过程。
The solution structure of ganglioside G(M1) carbohydrate moiety at the surface of a 102-kDa lipid-modified-G(M1) micelle is investigated by high-resolution H-1-NMR in H2O. The micellar surface can be considered a cluster-like lateral distribution of the gangliosides, each single monomer being anchored in a carbohydrate-enriched model membrane matrix. H-1 NOESY measurements at short mixing times reveal a rigid trisaccharide core -beta-GalNAc-(1-4)-[alpha-Neu5Ac-(2-3)]-beta-Gal- and a more flexible beta-Gal-(1-3)-beta-GalNAc- terminal glycosidic bond. in the lipid-modified G(M1) ganglioside micellar system, there is no evidence that intermolecular side-by-side carbohydrate interactions modulate, or alter in any way, the head-group spatial arrangement. Possible intermonomer interactions at the level of the branched trisaccharide portion were further investigated on mixed micelles of natural N-glycolyl- and N-acetylneuraminic acid containing G(M1) in D2O, taking advantage of the different NMR features of N-glycoyl- and N-acetylneuraminic acids, which allow discrimination between sialic acid ring proton signals. Measurements of the water/ganglioside-OH proton chemical exchange rates suggest hydroxyl group involvement at position 8 of sialic acid in strong intramolecular interaction processes.