» Articles » PMID: 39165727

Sialylation-induced Stabilization of Dynamic Glycoprotein Conformations Unveiled by Time-aligned Parallel Unfolding and Glycan Release Mass Spectrometry

Overview
Journal Chem Sci
Specialty Chemistry
Date 2024 Aug 21
PMID 39165727
Authors
Affiliations
Soon will be listed here.
Abstract

Sialylation, a critical post-translational modification, regulates glycoprotein structure and function by tuning their molecular heterogeneity. However, characterizing its subtle and dynamic conformational effects at the intact glycoprotein level remains challenging. We introduce a glycoform-resolved unfolding approach based on a high-throughput ion mobility-mass spectrometry (IM-MS) platform. This method integrates high-throughput unfolding with parallel fragmentation, enabling simultaneous analysis of sialylation patterns, stoichiometries, and their impact on conformational stability. Applying this approach to fetuin, we identified distinct sialylation patterns and their differential influence on protein conformation, namely sialylation-induced stabilization during early unfolding and increased flexibility in later unfolding stages. IM-MS-guided molecular dynamics simulations revealed that increased sialylation enhances the initial conformational stability, likely through enhanced electrostatic interactions and hydrogen bonding. These findings highlight the complex interplay between sialylation and protein dynamics and establish glycoform-resolved unfolding IM-MS as a powerful tool for characterizing glycoprotein conformational landscapes.

References
1.
Gabelica V, Shvartsburg A, Afonso C, Barran P, Benesch J, Bleiholder C . Recommendations for reporting ion mobility Mass Spectrometry measurements. Mass Spectrom Rev. 2019; 38(3):291-320. PMC: 6618043. DOI: 10.1002/mas.21585. View

2.
Li G, DeLaney K, Li L . Molecular basis for chirality-regulated Aβ self-assembly and receptor recognition revealed by ion mobility-mass spectrometry. Nat Commun. 2019; 10(1):5038. PMC: 6834639. DOI: 10.1038/s41467-019-12346-8. View

3.
Halim A, Westerlind U, Pett C, Schorlemer M, Ruetschi U, Brinkmalm G . Assignment of saccharide identities through analysis of oxonium ion fragmentation profiles in LC-MS/MS of glycopeptides. J Proteome Res. 2014; 13(12):6024-32. DOI: 10.1021/pr500898r. View

4.
Harvey D . Fragmentation of negative ions from carbohydrates: part 1. Use of nitrate and other anionic adducts for the production of negative ion electrospray spectra from N-linked carbohydrates. J Am Soc Mass Spectrom. 2005; 16(5):622-30. DOI: 10.1016/j.jasms.2005.01.004. View

5.
Shantha Raju T, Lang S . Diversity in structure and functions of antibody sialylation in the Fc. Curr Opin Biotechnol. 2014; 30:147-52. DOI: 10.1016/j.copbio.2014.06.014. View