人乳铁蛋白聚糖的一级结构。

Primary structure of the glycans from human lactotransferrin.

作者信息

Spik G, Strecker G, Fournet B, Bouquelet S, Montreuil J, Dorland L, van Halbeek H, Vliegenthart J F

出版信息

Eur J Biochem. 1982 Jan;121(2):413-9. doi: 10.1111/j.1432-1033.1982.tb05803.x.

DOI:10.1111/j.1432-1033.1982.tb05803.x

Abstract

The polypeptide chain of human lactotransferrin possesses two glycoslyation sites to which glycans are linked through an N-(beta-aspartyl)-N-acetylglucosaminylamine bond and which are structurally heterogenous. After chymotryptic or pronase digestions, glycopeptides with five different glycan structures could be isolated. For three of them, the structure has been determined by the application of methanolysis, methylation analysis, hydrazinolysis/nitrous deamination, enzymatic cleavage and 1H-NMR spectroscopy at 360 MHz: Glycopeptides A and B: NeuAc(alpha 2-6)Gal(beta 1-4)GlcNAc(beta 1-2)Man(alpha 1-3)[NeuAc(alpha 2-6)Gal(beta 1-4)GlcNAc(beta 1-2)Man(alpha 1-6)]Man(beta 1-4)GlcNAc(beta-1-4)[Fuc(alpha 1-6)]GlcNAc(beta 1-)Asn; Glycopeptide C: NeuAc(alpha 2-6)(Gal(beta 1-4)GlcNAc(beta 1-2)Man(alpha 1-3)(Gal(beta 1-4)[Fuc(alpha 1-3)]GlcNAc(beta 1-2)Man(alpha 1-6))Man(beta 1-4)GlcNAc(beta 1-4)[Fuc(alpha 1-6)]GlcNAc(beta 1-)Asn. Glycopeptide D: NeuAc(alpha 2-6)Gal(beta 1-4)GlcNAc(beta 1-2)Man(alpha 1-3)[Gal(beta 1-4)GlcNAc(beta 1-2)Man(alpha 1-6)]Man(beta 1-4)Glc-NAc(beta 1-4)[Fuc(alpha 1-6)]GlcNAc(beta 1-)Asn. Two other glycopeptides were obtained in very low amount and possess more complex structures.

摘要

人乳铁蛋白的多肽链有两个糖基化位点，聚糖通过N-（β-天冬氨酰基）-N-乙酰葡糖胺键与之相连，且结构各异。经胰凝乳蛋白酶或链霉蛋白酶消化后，可分离出具有五种不同聚糖结构的糖肽。其中三种糖肽的结构已通过甲醇解、甲基化分析、肼解/亚硝酸脱氨、酶切和360兆赫的1H-NMR光谱确定：糖肽A和B：NeuAc（α2-6）Gal（β1-4）GlcNAc（β1-2）Man（α1-3）[NeuAc（α2-6）Gal（β1-4）GlcNAc（β1-2）Man（α1-6）]Man（β1-4）GlcNAc（β-1-4）[Fuc（α1-6）]GlcNAc（β1-）Asn；糖肽C：NeuAc（α2-6）（Gal（β1-4）GlcNAc（β1-2）Man（α1-3）（Gal（β1-4）[Fuc（α1-3）]GlcNAc（β1-2）Man（α1-6））Man（β1-4）GlcNAc（β1-4）[Fuc（α1-6）]GlcNAc（β1-）Asn。糖肽D：NeuAc（α2-6）Gal（β1-4）GlcNAc（β1-2）Man（α1-3）[Gal（β1-4）GlcNAc（β1-2）Man（α1-6）]Man（β1-4）Glc-NAc（β1-4）[Fuc（α1-6）]GlcNAc（β1-）Asn。另外两种糖肽产量极低，结构更为复杂。