Development of a PNGase Rc Column for Online Deglycosylation of Complex Glycoproteins during HDX-MS

J Am Soc Mass Spectrom. 2023 Nov 1;34(11):2556-2566. doi: 10.1021/jasms.3c00268. Epub 2023 Sep 27.

Abstract

Protein glycosylation is one of the most common PTMs and many cell surface receptors, extracellular proteins, and biopharmaceuticals are glycosylated. However, HDX-MS analysis of such important glycoproteins has so far been limited by difficulties in determining the HDX of the protein segments that contain glycans. We have developed a column containing immobilized PNGase Rc (from Rudaea cellulosilytica) that can readily be implemented into a conventional HDX-MS setup to allow improved analysis of glycoproteins. We show that HDX-MS with the PNGase Rc column enables efficient online removal of N-linked glycans and the determination of the HDX of glycosylated regions in several complex glycoproteins. Additionally, we use the PNGase Rc column to perform a comprehensive HDX-MS mapping of the binding epitope of a mAb to c-Met, a complex glycoprotein drug target. Importantly, the column retains high activity in the presence of common quench-buffer additives like TCEP and urea and performed consistent across 114 days of extensive use. Overall, our work shows that HDX-MS with the integrated PNGase Rc column can enable fast and efficient online deglycosylation at harsh quench conditions to provide comprehensive analysis of complex glycoproteins.

MeSH terms

  • Glycoproteins* / analysis
  • Glycosylation
  • Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase
  • Polysaccharides* / metabolism

Substances

  • Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase
  • Glycoproteins
  • Polysaccharides