Kinetics of a finite one-dimensional spin system as a model for protein folding.

Simple spin models are used to analyze the kinetic nature of lowest energy state formation of the spin systems as models of protein folding kinetics. The models employed in the present paper are based on the spin systems as models of biopolymers previously proposed by the author for the analysis of the equilibrium nature of transitions [T. Kikuchi, Biophys. Chem. 65 (1997) 109]. In particular, the effect of frustrations on the kinetics is investigated with the Monte Carlo simulations in this study. The results show that the kinetics of the present systems are characterized by the ratio of foldables (pathways on the energy landscape that to lead to the lowest energy state) and the temperature dependence of the mean first passage time of foldables. We also discuss the free energy profile of the present models and the relation of the present results to the kinetics of actual proteins.