The formation of UA pAMAC probably occurred after OH had attacked at C-4 thus creating a new reducing terminus.
The hydrazinolysis approach is applicable for N-glycans as well as O-glycans [ 7, 18, 19], yielding glycans with a free reducing terminus.
Several other disadvantages of the hydrazinolysis method have been given by various groups: one example is the release of O-glycans by hydrazinolysis, which has to be followed by re-N-acetylation and a concomitant acetohydrazone cleavage step, which is crucial in order to obtain intact glycans with a free reducing terminus [ 7, 9, 18– 23].
Normally, a polysaccharide is considered to possess only a single oxo group: its reducing terminus.
Spot 2A is clearly not GalA2 pAMAC itself (a disaccharide with pAMAC at the former reducing terminus) because this would have been digested by Driselase to GalA pAMAC plus free GalA within 7 14 days.
OH attack is expected to introduce oxo groups rather indiscriminately along a polysaccharide chain, thus mostly not at the reducing terminus.
Notably, the anomeric configuration at the reducing terminus of the glycan has a pronounced effect on glycan presentation, which was not captured fully in the data in Table II.
A novel hydroxylated Fused-Core silica material has high utility for HILIC separation of reducing terminus labeled N-linked glycans.
Pullulan was selectively functionalized at its reducing terminus via reductive amination of the terminal aldehyde with 2- 4-nitrophenyl)ethylamine.
These results indicate that the bulk of the negatively charged material derived from EBV CDG Ig cells corresponds to phosphorylated Man7GlcNAc2 and that the phosphate is attached to the GlcNAc residue at the reducing terminus of the oligosaccharide.
In the presence of NaCNBH3 (sodium cyanoborohydride), AMAC will reductively aminate oxo groups, and will therefore label the reducing terminus and presumably also any OH-generated oxo groups.
