Glycopolymers stabilize protein folding and protein–protein interactions via enthalpic interactions

Sabrina M. Richter; Neal Brook; Alex J. Guseman

doi:10.1002/pro.70403

journal article Open Access Dec 22, 2025

Glycopolymers stabilize protein folding and protein–protein interactions via enthalpic interactions

Sabrina M. Richter Neal Brook Alex J. Guseman

Protein Science Vol. 35 No. 1 · Wiley

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Abstract

Abstract

Macromolecular crowding is ubiquitous in physiological environments, perturbing the thermodynamics and kinetics of proteins via excluded volume and nonspecific chemical interactions. While crowding has been well studied in vitro and in cells, the inert sugar polymers used to simulate crowding lack the chemical characteristics of biomolecules. Emerging studies guide the development of more relevant models of crowding in the cell, but little work has been done to discern crowding effects on proteins at the cell surface. Using
19
F NMR, we measure how protein stability, folding, and intermolecular interactions are modulated by three glycopolymers abundant at the cellular exterior. Biologically relevant glycopolymers including heparin, hyaluronic acid, and mucin significantly stabilize the folding of the N‐terminal domain of the Drk‐SH3 protein. These interactions are enthalpically stabilizing, emphasizing the importance of chemical interactions for biologically relevant crowders. We further show that these glycopolymers stabilize a homodimer formed by the A34F variant of GB1, demonstrating that biological crowders not only affect isolated proteins, but also influence how proteins interact with one another. Crowding is more complex than simple ideas of volume exclusion suggest, and our work guides a more comprehensive understanding of protein crowding in the context of the glycocalyx, the last frontier of the cell.

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Details

Published: Dec 22, 2025
Vol/Issue: 35(1)
License: View

Authors

S

Sabrina M. Richter

Department of Chemistry and Biochemistry University of California San Diego California USA

N

Neal Brook

Department of Chemistry and Biochemistry University of California San Diego California USA

A

Alex J. Guseman

Department of Chemistry and Biochemistry University of California San Diego California USA

Funding

National Institute of General Medical Sciences Award: R00GM145970

Cite This Article

Sabrina M. Richter, Neal Brook, Alex J. Guseman (2025). Glycopolymers stabilize protein folding and protein–protein interactions via enthalpic interactions. Protein Science, 35(1). https://doi.org/10.1002/pro.70403

Glycopolymers stabilize protein folding and protein–protein interactions via enthalpic interactions

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