Esterification Reaction: An Unexpected Side Reaction During Glycopeptide and Glycan Storages in Formic Acid Solution

ABSTRACT: Glycosylation is one of the most important co- and post-translational modifications on proteins. In glycomics and glycoproteomics studies, the released glycans or intact glycopeptides are analyzed by tandem mass spectrometry to achieve their large-scale analyses. Prior to LC-MS/MS analyses, the glycan and intact glycopeptide samples are normally dissolved in formic acid (FA) solution, and sometimes stored at -20 °C or lower temperatures. In this study, we show that an unexpected +28 Da modification would occur in a time-dependent manner when the glycan and glycopeptide samples were stored in FA solution at -20 °C. Additional evidences suggested that this unexpected modification should be mainly caused by the esterification reaction between the hydroxyl group of glycans and FA. As this modification would reduce the glycopeptide identification and/or increase false positive results, once the glycan and glycopeptide samples have been dissolved in FA solution, it should not be stored at -20 °C.

INSTRUMENT(S):

ORGANISM(S): Mus Musculus (mouse)

TISSUE(S): Brain, Kidney

SUBMITTER: Liuyi Dang  

LAB HEAD: Sun Shisheng

PROVIDER: PXD023448 | Pride | 2025-12-22

REPOSITORIES: Pride