Helix or Coil? Fate of a Melting Heteropolymer

TL;DR

This paper analyzes the melting behavior of heteropolymers, modeling the probability of complete melting or refolding as a stochastic process influenced by sequence disorder, revealing a transition from unimodal to bimodal melting probabilities.

Contribution

It introduces a stochastic model linking heteropolymer melting to Sinai diffusion, highlighting how sequence disorder affects melting probability distributions.

Findings

Melting probability fluctuates with monomer sequence.

Distribution shifts from unimodal to bimodal with increased disorder.

Model connects heteropolymer melting to Sinai diffusion.

Abstract

We determine the probability that a partially melted heteropolymer at the melting temperature will either melt completely or return to a helix state. This system is equivalent to the splitting probability for a diffusing particle on a finite interval that moves according to the Sinai model. When the initial fraction of melted polymer is f, the melting probability fluctuates between different realizations of monomer sequences on the polymer. For a fixed value of f, the melting probability distribution changes from unimodal to a bimodal as the strength of the disorder is increased.