Surface adsorption of lattice HP proteins: Thermodynamics and structural transitions using Wang-Landau sampling

TL;DR

This study uses Wang-Landau sampling to explore the thermodynamics and structural phase transitions of a lattice HP protein model interacting with an attractive substrate, revealing key adsorption and folding behaviors.

Contribution

It applies Wang-Landau sampling to analyze the thermodynamics and structural transitions of a lattice HP protein model near an attractive surface, highlighting the sequence of phase transitions.

Findings

Identification of adsorption, hydrophobic core formation, and flattening transitions.

Dependence of transition sequence on surface attraction strength.

Observation of structural phase transitions through specific heat analysis.

Abstract

Wang-Landau sampling has been applied to investigate the thermodynamics and structural properties of a lattice hydrophobic-polar heteropolymer (the HP protein model) interacting with an attractive substrate. For simplicity, we consider a short HP sequence consisting of only 36 monomers interacting with a substrate which attracts all monomers in the sequence. The conformational "phase transitions" have been identified by a canonical analysis of the specific heat and suitable structural observables. Three major "transitions", namely, adsorption, hydrophobic core formation and "flattening" of adsorbed structures, are observed. Depending on the surface attractive strength relative to the intra-protein attraction among the H monomers, these processes take place in different sequences upon cooling.