N-glycan structures of murine hippocampus serine protease, neuropsin, produced in Trichoplusia ni cells

N-glycans of neuropsin (serine protease in the murine hippocampus) expresse d in Trichoplusia ni cells were released from the glycopeptides by digestio n with glycoamidase A (from sweet almond), and the reducing ends of the oli gosaccharides were reductively aminated with 2-aminopyridine. The derivatiz ed N-glycans were separated and structurally identified by a two dimensiona l high-performance liquid chromatography (HPLC) mapping technique on two ki nds of HPLC columns. Fourteen different major N-glycan structures were iden tified, of which 6 were high-mannose type (9.1%), and the remaining 8 were paucimannosidic type. The presence of insect specific N-glycan structures c ontaining both alpha 1,3- and alpha 1,6- di-fucosylated innermost N-acetylg lucosamine residue (23.3%), as below, was also confirmed by 600 MHz H-1-NMR spectroscopy. [GRAPHICS]