Robbe Catherine, Capon Calliope, Coddeville Bernadette, Michalski Jean-Claude
Unité Mixte de Recherche CNRS/USTL 8576, 'Glycobiologie Structurale et Fonctionnelle', IFR 118, Université des Sciences et Technologies de Lille 1, 59655 Villeneuve d'Ascq Cedex, France.
Rapid Commun Mass Spectrom. 2004;18(4):412-20. doi: 10.1002/rcm.1352.
Nano-electrospray ionization quadrupole time-of-flight mass spectrometry (nanoESI-Q-TOFMS) was used for sensitive mapping and sequencing of underivatized oligosaccharide alditols obtained from human mucins. Using subnanomolar amounts of oligosaccharides previously analyzed by nuclear magnetic resonance (NMR), series of diagnostic ions relevant to the structural characterization of O-glycans were deduced. Determination of the core type as well as positions and partial linkages of fucose residues could be readily obtained from the dominant M+Na ions. Differentiation of isomeric structures and glycosidic linkages were defined by the characteristic cross-ring (0,2)A-type cleavages in the negative ion mode. Tandem (MS/MS) mass spectra of M-H ions from sialylated or sulfated O-glycans revealed information concerning the position and linkage of such residues. These fragmentation rules were further applied in the structural determination of glycans from human colonic mucins. All these findings indicated the efficiency of ESI-Q-TOFMS for the determination of oligosaccharide composition, sequence, partial linkage and substitution, providing a wealth of structural information with sensitivity sufficient for the analysis of quantities as obtained from natural sources.
纳米电喷雾电离四极杆飞行时间质谱（nanoESI-Q-TOFMS）用于对从人黏蛋白中获得的未衍生化低聚糖糖醇进行灵敏的图谱绘制和测序。使用先前通过核磁共振（NMR）分析过的亚纳摩尔量的低聚糖，推导出了一系列与O-聚糖结构表征相关的诊断离子。从主要的M+Na离子中可以轻松确定核心类型以及岩藻糖残基的位置和部分连接情况。在负离子模式下，通过特征性的跨环(0,2)A-型裂解来定义异构体结构和糖苷键的差异。来自唾液酸化或硫酸化O-聚糖的M-H离子的串联（MS/MS）质谱揭示了有关此类残基位置和连接的信息。这些裂解规则进一步应用于人类结肠黏蛋白聚糖的结构测定。所有这些发现表明ESI-Q-TOFMS在确定低聚糖组成、序列、部分连接和取代方面的有效性，能够提供丰富的结构信息，其灵敏度足以分析从天然来源获得的量。
