人乳转移酶对分支血型I型寡聚（N-乙酰乳糖胺）聚糖的α1,3-岩藻糖基化作用仅限于远端N-乙酰乳糖胺单元：所得异构体通过WGA-琼脂糖色谱法分离。
alpha 1,3-Fucosylation of branched blood group I-type oligo-(N-acetyllactosamino)glycans by human milk transferases is restricted to distal N-acetyllactosamine units: the resulting isomers are separated by WGA-agarose chromatography.
作者信息
Niemelä R, Natunen J, Brotherus E, Saarikangas A, Renkonen O
机构信息
Institute of Biotechnology, University of Helsinki, Finland.
出版信息
Glycoconj J. 1995 Feb;12(1):36-44. doi: 10.1007/BF00731866.
A partially purified preparation of alpha 1,3-fucosyltransferase(s) from human milk was used to [14C]fucosylate oligosaccharides containing Gal beta 1-4GlcNAc units. Substitution of N-acetyllactosamine at position 3' with a beta-linked N-acetyl-glucosamine enhanced the reactivity of the acceptor, whereas similar substitution at position 6' was inhibitory. Thus, the trisaccharide GlcNAc beta 1-6Gal beta 1-4GlcNAc (5), the branched tetrasaccharide GlcNAc beta 1-3(GlcNAc beta 1-6)Gal beta 1-4GlcNAc (11) and the triply branched decasaccharide GlcNAc beta 1-3(GlcNAc beta 1-6)Gal beta 1-4GlcNAc beta 1-3[GlcNAc beta 1-3(GlcNAc beta 1-6)Gal beta 1-4GlcNAc beta 1-6]Gal beta 1-4GlcNAc (26) gave remarkably poor yields of alpha 1,3-fucosylated products in comparison to GlcNAc beta 1-3Gal beta 1-4GlcNAc (3). beta 1,4-Galactosyl derivatives of 5 and 11, however, gave good yields of alpha 1,3-fucosylated products, but the fucosylation was restricted to the distal N-acetyllactosamine units of Gal beta 1-4GlcNAc beta 1-6Gal beta 1-4GlcNAc (16), Gal beta 1-4GlcNAc beta 1-3(Gal beta 1-4GlcNAc beta 1-6)Gal beta 1-4GlcNAc (18) and also in Gal alpha 1-3Gal beta 1-4GlcNAc beta 1-3(Gal alpha 1-3Gal beta 1-4GlcNAc beta 1-6)Gal beta 1-4GlcNAc (22). Immobilized wheat germ agglutinin (WGA), possessing high affinity for 16 [1], revealed no affinity for the fucosylated derivative Gal beta 1-4(Fuc alpha 1-3)GlcNAc beta 1-6Gal beta 1-4GlcNAc (17). The isomeric heptasaccharides Gal beta 1-4(Fuc alpha 1-3)GlcNAc beta 1-3(Gal beta 1-4GlcNAc beta 1-6)Gal beta 1-4GlcNAc (19) and Gal beta 1-4GlcNAc beta 1-3[Gal beta 1-4(Fuc alpha 1-3)GlcNAc beta 1-6]Gal beta 1-4GlcNAc (20) were readily separated from each other on WGA agarose, and so were the isomeric nonasaccharides Gal alpha 1-3Gal beta 1-4(Fuc alpha 1-3)GlcNAc beta 1-3(Gal alpha 1-3Gal beta 1-4GlcNAc beta 1-6)Gal beta 1-4GlcNAc (23) and Gal alpha 1-3Gal beta 1-4GlcNAc beta 1-3[Gal alpha 1-3Gal beta 1-4(Fuc alpha 1-3)GlcNAc beta 1-6]Gal beta 1-4GlcNAc (24).
使用从人乳中部分纯化的α1,3 - 岩藻糖基转移酶制剂对含有Galβ1 - 4GlcNAc单元的寡糖进行[14C]岩藻糖基化。在3'位用β - 连接的N - 乙酰葡糖胺取代N - 乙酰乳糖胺可增强受体的反应性，而在6'位进行类似取代则具有抑制作用。因此，与GlcNAcβ1 - 3Galβ1 - 4GlcNAc（3）相比，三糖GlcNAcβ1 - 6Galβ1 - 4GlcNAc（5）、分支四糖GlcNAcβ1 - 3(GlcNAcβ1 - 6)Galβ1 - 4GlcNAc（11）和三重分支十糖GlcNAcβ1 - 3(GlcNAcβ1 - 6)Galβ1 - 4GlcNAcβ1 - 3[GlcNAcβ1 - 3(GlcNAcβ1 - 6)Galβ1 - 4GlcNAcβ1 - 6]Galβ1 - 4GlcNAc（26）产生的α1,3 - 岩藻糖基化产物的产率极低。然而，5和11的β1,4 - 半乳糖基衍生物产生了良好产率的α1,3 - 岩藻糖基化产物，但岩藻糖基化仅限于Galβ1 - 4GlcNAcβ1 - 6Galβ1 - 4GlcNAc（16）、Galβ1 - 4GlcNAcβ1 - 3(Galβ1 - 4GlcNAcβ1 - 6)Galβ1 - 4GlcNAc（18）以及Galα1 - 3Galβ1 - 4GlcNAcβ1 - 3(Galα1 - 3Galβ1 - 4GlcNAcβ1 - 6)Galβ1 - 4GlcNAc（22）中远端的N - 乙酰乳糖胺单元。固定化麦胚凝集素（WGA）对16具有高亲和力[1]，但对岩藻糖基化衍生物Galβ1 - 4(Fucα1 - 3)GlcNAcβ1 - 6Galβ1 - 4GlcNAc（17）没有亲和力。异构体七糖Galβ1 - 4(Fucα1 - 3)GlcNAcβ1 - 3(Galβ1 - 4GlcNAcβ1 - 6)Galβ1 - 4GlcNAc（19）和Galβ1 - 4GlcNAcβ1 - 3[Galβ1 - 4(Fucα1 - 3)GlcNAcβ1 - 6]Galβ1 - 4GlcNAc（20）在WGA琼脂糖上很容易相互分离，异构体九糖Galα1 - 3Galβ1 - 4(Fucα1 - 3)GlcNAcβ1 - 3(Galα1 - 3Galβ1 - 4GlcNAcβ1 - 6)Galβ1 - 4GlcNAc（23）和Galα1 - 3Galβ1 - 4GlcNAcβ1 - 3[Galα1 - 3Galβ1 - 4(Fucα1 - 3)GlcNAcβ1 - 6]Galβ1 - 4GlcNAc（24）也是如此。
Zotero 插件