Negative Ion CID Fragmentation of O-linked Oligosaccharide Aldoses—Charge Induced and Charge Remote Fragmentation

• DOI: 10.1007/s13361-011-0102-3
• Publication Date: 2011-03-30T13:22:28Z
• Authors: Roisin A. Doohan; Catherine A. Hayes; Brendan Harhen; Niclas Göran Karl...
• Keywords: Fragmentation; Collision-induced dissociation

Collision induced dissociation (CID) fragmentation was compared between reducing and reduced sulfated, sialylated, neutral O-linked oligosaccharides. It found that of the [M - H](-) ions aldoses with acidic residues gave unique Z-fragmentation end GalNAc containing C-6 branch, where entire C-3 branch lost. This pathway, which is not seen in alditols, showed process involved charge remote catalyzed by a anomeric proton. With structures sialic acid on both were dominated loss acid. pathway also pronounced 2H](2-) revealing Z-fragment plus its complementary C-fragment addition to glycosidic cross ring fragmentation. generation Z/C-fragment pairs from charges participating their generation. Fragmentation believed be generated proton migration negatively charged residue followed similar In addition, A-type fragments oligosaccharides observed when migrated C-1 GlcNAc rearrangement accommodate (0,2)A-fragmentation. LC-MS existed as interchangeable α/β pyranose anomers, third isomer (25% total free aldose) furanose form.