PROTEIN-FOLDING AND MODELS OF DYNAMICS ON THE LATTICE

We study folding in 16-monomer heteropolymers on the square lattice. F or a given sequence, thermodynamic properties and stability of the nat ive state are unique. However, the kinetics of folding depends on the model of dynamics adopted for the time evolution of the system. We con sider three such models: Rouse-Like dynamics with either single monome r moves or with single and double monomer moves, and the ''slithering snake'' dynamics. Usually, the snake dynamics has poorer folding prope rties compared to the Rouse-like dynamics, but examples of opposite be havior can also be found. This behavior relates to which conformations act as local energy minima when their stability is checked against th e moves of a particular dynamics. A characteristic temperature related to the combined probability, P-L, to stay in the non-native minima du ring folding coincides with the temperature of the Fastest folding. St udies of P-L yield an easy numerical way to determine conditions of th e optimal folding. (C) 1998 American Institute of Physics. [S0021-9606 (98)50343-1].