Inspired by the protein folding problem, we propose a Rubik's cube model and study its thermodynamic and kinetic behavior. We find that the energy landscape contains a tiny funnel-like region, as the dynamics towards the native state is mostly diffusive. In particular, from Monte Carlo simulations we observe exponential kinetics in the first-passage-time distribution towards the native state at all temperatures considered, while the complexity of the energy landscape is exhibited through a stretched-exponential relaxation of the energy autocorrelation function. The rollover feature in the mean first passage time, as observed in many protein-folding dynamics studies, is captured again in our model and discussed under the statistical energy landscape approach.
- 82.20.-w Chemical kinetics and dynamics
- 82.37.Np Single molecule reaction kinetics, dissociation, etc.