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Structural assignment of disialylated biantennary N‐glycan isomers derivatized with 2‐aminopyridine using negative‐ion multistage tandem mass spectral matching
Author(s) -
Ito Hiroki,
Yamada Kuriko,
Deguchi Kisaburo,
Nakagawa Hiroaki,
Nishimura ShinIchiro
Publication year - 2006
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/rcm.2824
Subject(s) - chemistry , electrospray ionization , glycan , ion , tandem mass spectrometry , analytical chemistry (journal) , mass spectrometry , linkage isomerism , 2 aminopyridine , sialic acid , collision induced dissociation , mass spectrum , electrospray , structural isomer , chromatography , stereochemistry , organic chemistry , glycoprotein , metal , biochemistry
To investigate the possibility of structural assignment based on negative‐ion multistage tandem mass (MS n ) spectral matching, four isomers of disialylated biantennary N‐glycans ( α 2‐6 and/or α 2‐3 linked sialic acid on α 1‐6 and α 1‐3 antennae) derivatized with 2‐aminopyridine (PA) were analyzed by employing high‐performance liquid chromatography/electrospray ionization linear ion trap time‐of‐flight mass spectrometry (HPLC/ESI‐LIT‐TOFMS), which uses helium gas for ion trapping and collision‐induced dissociation (CID). It is shown that the MS 2 spectra derived from each precursor ion [M−2H] 2− are reproducible and useful for distinguishing the four isomers. Thus, they can be assigned by negative‐ion MS 2 spectral matching based on correlation coefficients. In addition, MS 3 spectra derived from D‐type fragment ions clearly differentiate the α 2‐3‐ or α 2‐6‐linked sialic acid on the α 1‐6 antenna due to their characteristic spectral patterns. The C 4 ‐type fragment ions, which are produced from both the α 1‐6 and α 1‐3 antennae, show the characteristic MS 3 spectra reflecting α 2‐3‐ or α 2‐6‐ linkage type or a mixture of both types. Thus, the differentiation and assignment of these disialylated biantennary N‐glycan isomers can also be supported with the MS 3 spectra of C 4 ‐ and D‐type ions. Copyright © 2006 John Wiley & Sons, Ltd.