Lattice-model analysis of the effect of protein surface charge distribution on amorphous aggregation and condensation

Abstract

We describe a lattice model to analyze the effect of protein surface charge distributions on protein solubility, aggregation, and condensation. Surface charges were modeled by considering a protein as a cubic particle with each face covered by two negative and positive patches (net zero charge). Particles were moved to adjacent lattice points according to a Monte Carlo algorithm. We observed that proteins having the same isoelectric point can have distinct aggregation propensities, depending on surface charge arrangements. Furthermore, with regard to the effect of heterogeneous intracellular environment, mixing two particle types affected the aggregation properties of the individual type.