Lateral interactions between protein molecules adsorbed onto a planar interface

Abstract: This paper seeks to express the chemical potential for proteins on a surface in terms of number surface densitiy. Generalized Van der Waals (GVdW) theory and Virial hard disk theory are explored and fitted to experimental data by varying the hard disk radius. Additionnally Metropolis Monte Carlo simulations are used to simulate the interactions between proteins. Simulations are done on freely rotating proteins with the center of mass constrained to a 2D plane and employing the Widom insertion method to calculate the chemical potential. The theory, derivation and discussion of GVdW, Virial and Widom insertion are examined in this paper. Finally an interactive tool is included, which dynamically plots GVdW potentials. This tool is available online, both as source code and as a public web interface.