Matrix-assisted laser desorption/ionization mass spectrometry analysis of glycans with co-derivatization of asparaginyl-oligosaccharides

Anal Chim Acta. 2015 Oct 8:896:102-10. doi: 10.1016/j.aca.2015.09.028. Epub 2015 Sep 21.

Abstract

As one of the most prevalent and complex post-translational modifications in biological systems, proteins glycosylation has drawn considerable attention in recent decades. Dissociation of the carbohydrates from glycoproteins may be the prerequisite step of glycomics experiments, which commonly performed by specific proteolysis. In this study, an alternative strategy was reported with nonspecific proteolysis in coupling with co-derivatization of TMPP-Ac and methylamidation for glycan moieties analysis by MALDI-MS. With the co-derivatization, a permanent positive charge was introduced to the Asn-glycans and the carboxylic groups were neutralized by methylamidation simultaneously. As a result, approximately 20 and 50-fold enhancement in the detection sensitivity was achieved for asialo-Asn and disialo-Asn respectively in comparison to their native counterparts. Ultimately, this developed strategy was successfully validated using three model glycoproteins, including ribonuclease B, ovalbumin and transferrin.

Keywords: Co-derivatization; Glycan analysis; Matrix-assisted laser desorption/ionization mass spectrometry; Pronase E proteolysis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Asparagine / chemistry*
  • Polysaccharides / analysis*
  • Polysaccharides / chemistry*
  • Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization

Substances

  • Polysaccharides
  • Asparagine