Conformational gap and heat capacity peaks of short lattice polymers

Abstract

Abstract From a simple and exact approach, we investigated the thermodynamic behavior of short HP-polymers (composed of hydrophobic and polar coarse-grained monomers) on the square lattice, for lengths N < 20 residues. In particular, we analyzed the heat capacity excitation peak, showing the strong correlation between its occurrence, at low temperatures, and a sharp conformational gap from ground states to first excited states ( Ω 1 / Ω 0 ≫ 1 ). This relation is observed for both homopolymers and heteropolymers.