Freezing and folding behavior in simple off-lattice heteropolymers

TL;DR

This study uses parallel tempering Monte Carlo simulations on simple off-lattice heteropolymers, revealing first-order transitions to ordered states, contrasting with the predicted continuous glassy transitions by the random energy model.

Contribution

It demonstrates that simple continuum heteropolymer models exhibit first-order folding transitions, challenging existing theoretical predictions of continuous glassy behavior.

Findings

All studied sequences show first-order transitions at low temperature.

Transitions lead to ordered states dominated by single chain conformations.

Results contrast with the random energy model's predictions of continuous glassy transitions.

Abstract

We have performed parallel tempering Monte Carlo simulations using a simple continuum heteropolymer model for proteins. All ten heteropolymer sequences which we have studied have shown first-order transitions at low temperature to ordered states dominated by single chain conformations. These results are in contrast with the theoretical predictions of the random energy model for heteropolymers, from which we would expect continuous transitions to glassy behavior at low temperatures.