Facile sequencing of oligosaccharides by matrix-assisted laser desorption/ionisation on a hybrid quadrupole orthogonal acceleration time-of-flight mass spectrometer

N-Linked oligosaccharide mixtures released from a number of standard glycop roteins were derivatised with 3-acetylamino-6-acetylaminoacridine (AA-Ac) u sing reductive amination. Analysis of these mixtures using an experimental matrix-assisted laser desorption/ionisation (MALDI) hybrid quadrupole ortho gonal acceleration time-of-flight (Q-TOF) mass spectrometer provided detail ed information about the mass distribution of the glycan derivatives. Colli sion-induced dissociation of the singly protonated [M + H](+) ions also gav e rise to a number of product ions produced by the sequential cleavage of t he glycosidic linkages. As fragmentation of the positively charged species occurred predominantly in one direction, i.e., from the non-reducing end of the glycan to the AA-Ac moiety, a considerable amount of information could be obtained with ease about the sequence in which the sugar residues were attached to one another. This derivatisation procedure and mass spectrometr ic methodology were applied successfully to neutral and acidic glycans rele ased from proteins separated by gel electrophoresis. Copyright (C) 2001 Joh n Wiley & Sons, Ltd.