Title: Dimensional Dependence of Protein-protein Binding
Abstract: Protein-protein binding is central to most processes involved in cellular regulation. Proteins bind in solution (three-dimensional binding) as well as on membranes (two-dimensional binding). Dissociation constants are measurements of binding strengths and are typically measured in solution. It is often assumed that these three-dimensional measurements give direct insight into how tightly proteins bind when on membranes. However, mathematically, dissociation constants in two and three dimensions have different units. In this talk, I will present general, stochastic models of protein-protein binding in one, two, and three dimensions in discrete space with both no flux and periodic boundaries and in continuous space with periodic boundaries. Using stochastic exit time calculations, I will present dissociation constants in 1D, 2D, and 3D which demonstrate that binding is highly dependent on dimension. I will then present a novel formula for converting between 3D and 2D dissociation constants. Further, I will discuss important open questions in this field.