Miller K E, Mukhopadhyay C, Cagas P, Bush C A
Department of Chemistry & Biochemistry, University of Maryland Baltimore County 21228.
Biochemistry. 1992 Jul 28;31(29):6703-9. doi: 10.1021/bi00144a009.
The Lewis x (Lex) determinant is a trisaccharide fragment that has been implicated as a specific differentiation antigen, as a tumor antigen, and as a key component of the ligand for the endothelial leukocyte adhesion molecule, ELAM-1. High-resolution nuclear magnetic resonance spectroscopy shows it to have a relatively rigid structure. Only a small range of glycosidic dihedral angles in the trisaccharide produce simulated nuclear Overhauser effect spectra agreeing with data measured for the human milk pentasaccharide, lacto-N-fucopentaose-3, which contains the Lex determinant. Independently, the same average structure for the Lex determinant arises from in vacuo molecular dynamics simulations. The proposed conformation of the Lex trisaccharide is very similar to that recently determined for the closely related Lea trisaccharide. In agreement with the recent finding that both sialylated Lea and Lex react with ELAM-1, the results presented here show that the Lea and Lex determinants contain very similar carbohydrate domains.
Lewis x（Lex）决定簇是一种三糖片段，它被认为是一种特异性分化抗原、肿瘤抗原，也是内皮白细胞黏附分子ELAM - 1配体的关键组成部分。高分辨率核磁共振光谱显示其具有相对刚性的结构。三糖中只有一小范围的糖苷二面角能产生与含Lex决定簇的人乳五糖——乳糖 - N - 岩藻五糖 - 3测量数据相符的模拟核Overhauser效应光谱。独立地，Lex决定簇的相同平均结构也来自于真空分子动力学模拟。所提出的Lex三糖构象与最近确定的密切相关的Lea三糖构象非常相似。与最近发现的唾液酸化的Lea和Lex都与ELAM - 1反应一致，此处给出的结果表明Lea和Lex决定簇含有非常相似的碳水化合物结构域。
