Computationally and experimentally derived general rules for fragmentation of various glycosyl bonds in sodium adduct oligosaccharides.
Computationally and experimentally derived general rules for fragmentation of various glycosyl bonds in sodium adduct oligosaccharides.
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DOI：
10.1021/ac802230a
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发表时间：
2009-02
影响因子：
7.4
通讯作者：
Hiroaki Suzuki;A. Kameyama;K. Tachibana;H. Narimatsu;K. Fukui
中科院分区：
文献类型：
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作者：
Hiroaki Suzuki;A. Kameyama;K. Tachibana;H. Narimatsu;K. Fukui
通过使用计算计算来研究各种糖中糖基键连接的断裂机制，以找到质谱中钠化寡糖断裂的一般规则。计算表明，α-Glc、α-Gal、β-Man、α-Fuc、β-GlcNAc 和 beta-GalNAc 连接比 β-Glc、β-Gal 和 α-Man 连接更容易裂解，因为前者的过渡态通过异头效应得以稳定。 1-6键比其他键更稳定，因为具有柔性1-6键的糖在能量上比钠阳离子的其他键更稳定。唾液酸键是所有研究的键中最不稳定的。活化能和与钠阳离子的结合亲和力的比较揭示了活化能的增加与结合亲和力的增加成比例。计算出的糖基键稳定性为：α-Man (Manalpha1-3Man、Manalpha1-4Man、Manalpha1-6Man) > beta-Gal (Galbeta1-4Gal) > alpha-GalNAc (GalNAcalpha1-4GalNAc) > beta-Man (Manbeta1-4GlcNAc) > alpha-Gal (Galalpha1-3Gal、Galalpha1-4Gal、 Galalpha1-6Gal) > β-Man (Manbeta1-4Man) > β-GalNAc (GalNAcbeta1-4GalNAc) > α-Fuc (Fucalpha1-6GlcNAc) > α-Fuc (Fucalpha1-4GlcNAc) > β-GlcNAc (GlcNAcbeta1-4GlcNAc) > α-Fuc (Fucalpha1-3GlcNAc) > α-NeuNAc (NeuNAcalpha2-3Gal、NeuNAcalpha2-6Gal)；这个结果接近于实验推论的趋势。这些从理论上和实验上得出的碎裂一般规则对于分析实验获得的寡糖质谱应该是有用的。
Mechanisms of fragmentation of glycosyl bond linkages in various saccharides were investigated by using computational calculations to find general rules of fragmentation of sodiated oligosaccharides in mass spectrometry. The calculations revealed that alpha-Glc, alpha-Gal, beta-Man, alpha-Fuc, beta-GlcNAc, and beta-GalNAc linkages were cleaved more easily than beta-Glc, beta-Gal, and alpha-Man linkages because the transition states of the former were stabilized by the anomeric effect. The 1-6 linkage was more stable than the others, since saccharides with flexible 1-6 linkages were more stabilized in energy than the other linkages by the sodium cation. The sialyl linkage was the most labile of all the linkages investigated. Comparison of activation energies and binding affinities to the sodium cation revealed an increase in activation energy in proportion to the increment in binding affinity. The calculated stabilities of glycosyl bonds were: alpha-Man (Manalpha1-3Man, Manalpha1-4Man, Manalpha1-6Man) > beta-Gal (Galbeta1-4Gal) > alpha-GalNAc (GalNAcalpha1-4GalNAc) > beta-Man (Manbeta1-4GlcNAc) > alpha-Gal (Galalpha1-3Gal, Galalpha1-4Gal, Galalpha1-6Gal) > beta-Man (Manbeta1-4Man) > beta-GalNAc (GalNAcbeta1-4GalNAc) > alpha-Fuc (Fucalpha1-6GlcNAc) > alpha-Fuc (Fucalpha1-4GlcNAc) > beta-GlcNAc (GlcNAcbeta1-4GlcNAc) > alpha-Fuc (Fucalpha1-3GlcNAc) > alpha-NeuNAc (NeuNAcalpha2-3Gal, NeuNAcalpha2-6Gal); this result was close to the experimentally deduced trend. These theoretically and experimentally derived general rules for fragmentation should be useful for analyzing the experimentally obtained mass spectra of oligosaccharides.