2002/11/16 by Mai Suan Li, D. K. Klimov, D. Thirumalai
Physics and Astronomy · Biochemistry, Genetics and Molecular Biology · #cond-mat.soft #cond-mat.stat-mech #q-bio
published as J. Phys. Chem. B 106, 8302 (2002) · 6 pages, 5 eps figures
arxiv created 2002/11/16 · arxiv updated 2009/11/30
Using three-dimensional Go lattice models with side chains for proteins, we investigate the dependence of folding times on protein length. In agreement with previous theoretical predictions, we find that the folding time grows as a power law with the chain length N with exponent λ≈ 3.6 for the Go model, in which all native interactions (i.e., between all side chains and backbone atoms) are uniform. If the interactions between side chains are given by pairwise statistical potentials, which introduce heterogeneity in the contact energies, then the power law fits yield large λ values that typically signifies a crossover to an underlying activated process. Accordingly, the dependence of folding time is best described by the stretched exponential exp(√(N)). The study also shows that the incorporation of side chains considerably slows down folding by introducing energetic and topological frustration.