Conformational changes of globular proteins upon adsorption on a hydrophobic surface

Abstract

This paper presents a study of protein adsorption and denaturation using coarse-grained Monte Carlo simulations with simulated annealing. Intermolecular interactions are modeled using the Miyazawa–Jernigan (MJ) knowledge-based potential for an implicit solvent. Three different hydrophobicity scales are tested for adsorption of fibronectin on a hydrophobic surface. The hydrophobic scale BULDG was chosen for further analysis due to its greater stability during heating and its partial regenerative ability upon slow cooling. Differences between helical and sheet structures are observed upon denaturation – α-helices undergo spreading of their native helical order to an elliptical perturbed shape, while β-sheets transform into random coils and other more structured conformations. Electronic calculations carried out on rebuilt all-atom coordinates of adsorbed lysozymes revealed consistent destabilization of helices, while beta sheets show a greater variety of trends.