Bisected N-glycans
A number of complex structures with bisecting GlcNAc were present in
CTRL tear fluid profiles, including two very intense ions at m/z1906.9 and 2081.1 that correspond to the agalactosyl- biantennary
structure A2B and to the same structure core-fucosylated (FA2B),
respectively. Since permethylated bisected species showed no
characteristic fragments by MALDI MS/MS, structural characterization was
achieved by comparing the fragmentation spectra with the model compound
as already reported [13].