How does a β-hairpin fold/unfold? Competition between topology and heterogeneity in a solvable model

摘要

We study the competition between topological effects and se- quence inhomogeneities in determining the thermodynamics and the un/folding kinetics of a β-hairpin. Our work utilizes a new exactly salvable model that allows for arbitrary configurations of native contacts. In general, the competition between heterogene- ity and topology results in a crossover of the dominant transition state. Interestingly, near this crossover, the single reaction coor- dinate picture can be seriously misleading. Our results also suggest that inferring the folding pathway from unfolding simulations is not always justified.