Programme

O.28 -- Oral, VCTP-50

Date: Thursday, 7 August 2025

Time: 14:25 - 14:50

Solvation effects on protein folding in a simple lattice model

Nhung T. T. Nguyen (1,2), Pham Nam Phong (3), Duy Manh Le (4,5), Minh-Tien Tran (2), and Trinh Xuan Hoang (2)

(1) Graduate University of Science and Technology, Vietnamese Academy of Science and Technology, 18 Hoang Quoc Viet, Nghia Do, Cau Giay, Hanoi 11307, Vietnam (2) Institute of Physics, Vietnamese Academy of Science and Technology, 10 Dao Tan, Ba Dinh, Hanoi 11108, Vietnam (3) Faculty of Engineering Physics, Hanoi University of Science and Technology, 1 Dai Co Viet Road, Hanoi, Vietnam (4) Laboratory of Advanced Materials and Natural Resources, Institute for Advanced Study in Technology, Ton Duc Thang University, Ho Chi Minh City, Vietnam (5) Faculty of Applied Sciences, Ton Duc Thang University, Ho Chi Minh City, Vietnam

The aqueous solvent profoundly influences protein folding, yet its effects are relatively poorly understood. In this study, we investigate the impact of solvation on the folding of lattice proteins by using Monte Carlo simulations. The proteins are modeled as self-avoiding 27-mer chains on a cubic lattice, with compact native states and structure-based Go potentials. Each residue that makes no contact with other residues in a given protein conformation is assigned a solvation energy ε_s, representing its full exposure to the solvent. We find that a negative ε_s, indicating a favorable solvation, increases the cooperativity of the folding transition by lowering the free energy of the unfolded state, increasing the folding free energy barrier, and narrowing the folding routes. This favorable solvation also significantly improves the correlation between folding rates and the native topology, measured by the relative contact order. It is suggested that the solvation potential in our model is related to the polar interaction between water and peptide groups in the protein backbone.

Presenter: Nguyen Thi Thuy Nhung