Biomolecular phase boundaries are described by a solubility product that accounts for variable stoichiometry and soluble oligomers.

The solubility product is a rigorous description of the phase boundary for salt precipitation and has also been used to qualitatively describe the condensation of biomolecules. Here we present a derivation of the solubility product showing that the solubility product is also a robust description of biomolecules phase boundaries if care is taken to account for soluble oligomers and variable composition within the dense phase. Our calculation describes equilibrium between unbound monomers, the dense phase, and an ensemble of oligomer complexes with significant finite-size contributions to their free energy.

Competing addition processes give distinct growth regimes in the assembly of 1D filaments.

We present a model to describe the concentration-dependent growth of protein filaments. Our model contains two states, a low-entropy/high-affinity ordered state and a high-entropy/low-affinity disordered state. Consistent with experiments, our model shows a diffusion-limited linear growth regime at low concentration, followed by a concentration-independent plateau at intermediate concentrations, and rapid disordered precipitation at the highest concentrations.

Deformation of membrane vesicles due to chiral surface proteins.

Chiral, rod-like molecules can self-assemble into cylindrical membrane tubules and helical ribbons. They have been successfully modeled using the theory of chiral nematics. Models have also predicted the role of chiral lipids in forming nanometer-sized membrane buds in the cell.

Chiral molecules on curved colloidal membranes.

Colloidal membranes, self assembled monolayers of aligned rod like molecules, offer a template for designing membranes with definite shapes and curvature, and possibly new functionalities in the future. Often the constituent rods, due to their molecular chirality, are tilted with respect to the membrane normal. Spatial patterns of this tilt on curved membranes result from a competition among depletion forces, nematic interactions, molecular chirality and boundary effects.