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Updated: Dec 14, 2025
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Assembly and Characterization of Polyelectrolyte Complex Micelles
Published on: March 2, 2020
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Effect of Protein Surface Charge Distribution on Protein-Polyelectrolyte Complexation
Sieun Kim1, Hursh V Sureka1, A Basak Kayitmazer2
1Department of Chemical Engineering, Massachusetts Institute of Technology, 02139 Cambridge, Massachusetts, United States.
Biomacromolecules
|July 17, 2020
Summary
Protein surface charge patches significantly influence coacervation, driving complex formation and phase behavior. Increased charge patchiness promotes protein-polymer complexation and aggregation, impacting biomolecular condensates.
Area of Science:
- Biochemistry
- Biophysics
- Materials Science
Background:
- Protein surface charge distribution is hypothesized to influence coacervation behavior.
- Charge anisotropy may explain coacervation outside a protein's isoelectric point.
Purpose of the Study:
- To investigate the role of protein surface charge patchiness in driving coacervation.
- To quantify the relationship between charge patchiness and protein-polymer complex formation and phase behavior.
Main Methods:
- Engineered superfolder green fluorescent protein mutants with varied surface charge distributions but constant net charge.
- Utilized a patchiness parameter to quantify protein surface charge correlation.
- Studied complexation and phase behavior with strong and weak polyelectrolytes.
Main Results:
- Proteins with higher patchiness parameters exhibited increased complexation with polyelectrolytes.
- Increasing protein charge patchiness promoted macrophase separation and soluble aggregate formation.
- The effect of patchiness on phase behavior was dependent on the type of polyelectrolyte used.
Conclusions:
- Protein surface charge patchiness is a critical determinant of coacervation and phase behavior.
- Charge patchiness, rather than net charge alone, governs protein-polymer interactions.
- Understanding charge distribution is key for predicting and controlling biomolecular condensate formation.
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