Coacervation of Elastin-Like Polypeptides: A Coarse-Grained Perspective

Elastin-like polypeptides (ELPs) are a class of bioengineered polymers that mimic the hydrophobic repeat units of the precursor of the elastin protein. These segments drive self-aggregation, a process influenced by various stimuli such as temperature, pH, salt concentration, hydrophobicity of guest amino acid residues, etc. In this study, we employ coarse-grained molecular dynamics (CGMD) simulations using the Martini 3.0 force field to examine the effects of temperature and polymer concentration on the coacervation of (VPGIG)₂₀. Our analysis reveals that both temperature and polypeptide concentration enhance the process of coacervation of the ELP chains. Higher temperatures lead to stronger interchain interactions among polypeptides and weaker interactions with water, supported by a decrease in water number density during coacervate formation. Cluster analysis shows an increase in cluster size with temperature at low polypeptide concentration, while at higher concentration, clusters form earlier and become more compact with the temperature. Conformational analysis further supports this as chains tend to extend during coacervation at low concentration but adopt more collapsed conformations at higher concentration due to coacervate compaction. In brief, our study provides insights into the parameters influencing ELP coacervation, offering guidance for the design of tailored biopolymers for specific applications.