Atomistic and Coarse-grained Simulations of Thermoresponsive Biopolymers*

This talk focuses on our multi-scale simulation studies on thermoresponsive biopolymers, specifically elastin-like peptides (ELP) and collagen-like peptides (CLP). ELPs are biopolymers that undergo a lower critical solution temperature (LCST)-like phase transition, which means ELPs are soluble below the transition temperature, T_t, and insoluble above T_t. The T_t of ELPs can be tuned via conjugation to other thermoresponsive biomolecules such as CLPs. In our recent work, we used all-atom (AA) and coarse-grained (CG) simulations to elucidate how the guest residue impacts ELP stiffness, its secondary structure formation, and hydrophobicity and thus, the LCST-like transition of ELP and ELP-CLP conjugates. We used the structural data from AA simulations to modify our previous ELP CG model such that it captures the atomistically-informed stiffness while enabling simulations at experimentally relevant length scales. Our new ELP CG model also accounts for the hydrophobicity of the guest residue and its propensity to form compact, secondary structures. Through these modifications, our CG simulations are able to explain the experimental observations in T_t of ELP and ELP-CLP conjugates with W and F as the guest residues.