The bulk thermodynamic properties of membrane proteins originate from a complex combination of molecular interactions. We propose a simple model based on the pair interactions between a model membrane protein, annexin V. The experimental observations of a honeycomb (p6) and a triangular (p3) phase are successfully reproduced with Monte Carlo computer simulations. Grand canonical simulations and a newly developed "strip"-move constant pressure technique reveal the stability of a dilute fluid phase and a dense solid phase, not observed with the current experimental technology. While this model is extremely simple in that it relies only on hard-body and short-range directional interactions, it nevertheless captures the essential physics of the interactions between the protein molecules and reproduces the phase behavior observed in experiments.
J. Chem. Phys.

Bates, M. A., Noro, M. G., & Frenkel, D. (2002). Computer simulation of the phase behavior of a model membrane protein: Annexin V. J. Chem. Phys., 116, 7217–7224. doi:10.1063/1.1463423