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Updated: Jun 2, 2025
Synthesis of Information-bearing Peptoids and their Sequence-directed Dynamic Covalent Self-assembly
Published on: February 6, 2020
Biphasic Coacervation Controlled by Kinetics as Studied by De Novo-Designed Peptides
1Beijing National Laboratory for Molecular Sciences, Department of Polymer Science and Engineering and the Key Laboratory of Polymer Chemistry and Physics of the Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
Kinetics, not just thermodynamics, significantly influences coacervation (liquid-liquid phase separation). Peptide properties like charge and structure dictate whether kinetics or thermodynamics dominate phase separation, impacting coacervate formation and function.
Area of Science:
- Biomaterials Science
- Physical Chemistry
- Polymer Science
Background:
- Coacervation, a form of liquid-liquid phase separation, is typically governed by thermodynamics.
- However, complex systems with multiple interactions may involve significant kinetic contributions.
- Understanding these contributions is crucial for controlling coacervate properties.
Purpose of the Study:
- To investigate the role of kinetics in biphasic coacervate formation.
- To evaluate how peptide characteristics (charge density, hydrophobicity, secondary structure) influence kinetic control.
- To explore the implications of kinetic control for coacervate morphology and function.
Main Methods:
- Utilized peptides with tunable properties ((XXLY)6SSSGSS) to form coacervates with single-stranded oligonucleotides and quaternized dextran.
- Varied pH to alter electrostatic and hydrophobic interactions.
- Analyzed systems with single peptides and combinations of two different peptides.
Main Results:
- Kinetic effects on coacervation were negligible only when charge density was constant and electrostatics dominated.
- Path-dependent coacervation, indicating kinetic control, occurred when pH-dependent electrostatics, hydrophobic interactions, or peptide secondary structures were involved.
- In mixed peptide systems, higher charge density peptides initially dominated, followed by cooperative effects.
Conclusions:
- Coacervation processes can be significantly controlled by kinetics, leading to diverse coacervate morphologies and functions.
- Minimized peptide sequences offer a practical method for studying kinetics-driven coacervation mechanisms.
- Kinetic control is particularly relevant for coacervate behavior in biological systems like living cells.
