Analysis of N-acetylaminosugars by CE: a comparative derivatization study.
N-linked or O-linked glycans derived from glycoprotein processing carry, an N-acetylglucosamine or an N-acetylgalactosamine respectively, at their reducing termini. The presence of the N-acetylamino group on C-2 of reducing sugar residues has been reported to hamper the derivatization reaction with a chromophore at the anomeric centre. In this paper N-acetyllactosamine, N-acetylglucosamine, N-acetylgalactosamine and several other neutral monosaccharides are coupled to three different dyes (4-aminobenzonitrile, 2-aminopyridine, 2-aminobenzoic acid (2-AA)) by reductive amination and analysed by CE with UV detection. The 2-AA derivatives showed the lowest concentration detection limits, varying approximately in the 2-3 muM range for the saccharides tested including the N-acetamido ones. The possibility to separate and detect with the same sensitivity ten 2-AA-labelled monosaccharides mainly found in mammalian or plant glycoproteins in a single CE run is highlighted. The analysis has been carried out in less than 25 min using the borate-complexation method in CZE mode. The influence of the strength of the acid used as catalyst in the chemical modification of the sugars with 2-AA is also shortly addressed.
Rustighi
Isabella
I
Department of Life Sciences, University of Trieste, Trieste, Italy.
Campa
Cristiana
C
Rossi
Marco
M
Semeraro
Sabrina
S
Vetere
Amedeo
A
Gamini
Amelia
A
D000116:Acetylgalactosamine / Q000032:analysis; D000117:Acetylglucosamine / Q000032:analysis; D000606:Amino Sugars / Q000032:analysis*; D000631:Aminopyridines / Q000737:chemistry; D020374:Chromatography, Micellar Electrokinetic Capillary / Q000379:methods*; D019075:Electrophoresis, Capillary / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D009570:Nitriles / Q000737:chemistry; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D062367:ortho-Aminobenzoates / Q000737:chemistry
D000606:Amino Sugars; D000631:Aminopyridines; D009570:Nitriles; D062367:ortho-Aminobenzoates; C031385:anthranilic acid; D000116:Acetylgalactosamine; C045271:4-aminobenzonitrile; D000117:Acetylglucosamine; C032439:alpha-aminopyridine