Ionization and collision-induced fragmentation of N-linked and related carbohydrates using divalent canons
Ionization and collision-induced fragmentation of N-linked and related carbohydrates using divalent canons
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DOI：
10.1016/s1044-0305(01)00268-9
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发表时间：
2001-08-01
影响因子：
3.2
通讯作者：
Harvey, DJ
中科院分区：
文献类型：
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作者：
Harvey, DJ
麦芽七糖和几个N-连接的糖链被电极丝以加合物的形式与二价离子镁、钙、锰、钴和铜离子电离。[M+金属](2+)离子是所有病例中的主要形态，其中钙的敏感性最高。此外，铜还提供了[M+Cu](+)离子。另一些经典只能通过消除质子化的单糖来产生单电荷离子。[M+金属](2+)离子的碎裂既产生单电荷离子，又产生双电荷离子，双电荷离子的相对丰度按Ca&Gt；Mg&Gt；Mn&Gt；Co&Gt；Cu的顺序递减。单电荷离子是通过消除质子化的单糖残基，然后是连续的单糖残基损失，或者通过还原末端的单糖的(2，4)A跨环裂解而形成的。从[M+金属](2+)离子形成双电荷碎片涉及到连续的单糖残基损失，无论是否有(O，2)A或(2，4)A跨环裂解还原末端的单糖。(O，2)A交叉环产物中3-天线的缺失所形成的丰富的诊断双电荷离子是(M+Ca]2+离子所特有的。(M+Cu)(+)离子的碎裂与相应的[M+H](+)离子的碎裂相似，因为大多数交叉环碎片都没有。(C)2001年美国质谱学学会。
Maltoheptaose and several N-linked glycans were ionized by electros pray as adducts with the divalent canons Mg2+, Ca2+, Mn2+, Co2+ and Cu2+. [M + metal](2+) ions were the major species in all cases with calcium giving the highest sensitivity. In addition, copper gave [M + Cu](+) ions. Other canons gave singly charged ions only by elimination of a protonated monosaccharide. Fragmentation of the [M + metal](2+) ions produced both singly and doubly charged ions with the relative abundance of doubly charged ions decreasing in the order Ca > Mg > Mn > Co > Cu. Singly charged ions were formed by elimination of a protonated monosaccharide residue followed, either by successive monosaccharide residue losses, or by a (2,4)A cross-ring cleavage of the reducing-terminal monosaccharide. Formation of doubly charged fragments from [M + metal](2+) ions involved successive monosaccharide-residue losses either with or without (O,2)A or (2,4)A cross-ring cleavages of the reducing-terminal monosaccharide. Abundant diagnostic doubly charged ions formed by loss of the 3-antenna from the (O,2)A cross-ring product were specific to (M + Ca]2+ ions. Fragmentation of (M + Cu](+) ions was similar to that of the corresponding [M + H](+) ions in that most cross-ring fragments were absent. (C) 2001 American Society for Mass Spectrometry.