Blanken W M, van Vliet A, van den Eijnden D H
J Biol Chem. 1984 Dec 25;259(24):15131-5.
The branch specificity of bovine colostrum and calf thymus UDP-Gal:N-acetylglucosaminide beta-1----4-galactosyltransferase toward several branched oligosaccharides, which form part of the complex-type N-glycans of glycoproteins, was investigated. A novel method was used based on acetolysis of the bi[14C,3H] galactosylated oligosaccharide products formed by the enzymes in vitro and analysis of the acetolysis fragments by high-pressure liquid chromatography. It could be established that the galactosylation of different oligosaccharide branches occurred in a preferred order. No difference in branch specificity was observed between the soluble bovine colostrum galactosyltransferase and the enzyme that had been solubilized from calf thymus membranes. A preferential pathway for the biosynthesis of bisialylated biantennary glycans is proposed.
研究了牛初乳和小牛胸腺UDP-半乳糖：N-乙酰葡糖胺β-1----4-半乳糖基转移酶对几种分支寡糖的分支特异性，这些寡糖是糖蛋白复合型N-聚糖的一部分。采用了一种新方法，该方法基于对酶体外形成的双[14C,3H]半乳糖基化寡糖产物进行乙酰解，并通过高压液相色谱分析乙酰解片段。可以确定不同寡糖分支的半乳糖基化按优先顺序发生。在可溶性牛初乳半乳糖基转移酶和从小牛胸腺膜中溶解的酶之间未观察到分支特异性差异。提出了双唾液酸化双触角聚糖生物合成的优先途径。
