乙酰解方法测定痕量糖链中α1→6联接的分枝点

Branching Studies with al→6 Linkage of Trace Oligosaccharides Using Acetolysis

乙酰解能使糖链中的α1→6联接键优先断离,本文报道糖链的还原端接上对氨基苯甲酸乙酯(ABEE)后,应用HPLC分离部分乙酰解的复杂断离产物,正离子LSIMS测定它们的分子量并判断α1→6联接点,异麦芽八糖α1→6联结序列的测定证实改进后的乙酰解方法能获得满意的结果。此外还测定了μmol IgM样品中寡糖链的两个分枝点。

We have investigated the usefulness of preferential partial acetolysis of the α1→ 6 linkages in establishing homogeneity and branching of the oligosaccharide. The ethyl ester of p-aminobenzoic acid has been used to derivative the reducing termini of intact carbohydrates. The HPLC is effective to seperate the trace products of acetolysis. After determining the molecular weights using negative ion LSIMS, the branching can be characterized easily. using positive ion LSIMS The α 1→6 linkages of isomaltooctaose have been determined satisfactory using the advanced acetolysis. The branching of an high mannose oligosaccharides isolated from IgM have been determined at micromole level.