title: Finite Element Estimation of Protein-Ligand Association Rates with Post-Encounter Effects: Applications to Calcium binding in Troponin C and SERCA.
abstract: We introduce a computational pipeline and suite of software tools for the approximation of diffusion-limited binding based on a recently developed theoretical framework. Our approach handles molecular geometries generated from high-resolution structural data and can account for active sites buried within the protein or behind gating mechanisms. Using tools from the FEniCS library and the APBS solver, we implement a numerical code for our method and study two Ca(2+)-binding proteins: Troponin C and the Sarcoplasmic Reticulum Ca(2+) ATPase (SERCA). We find that a combination of diffusional encounter and internal 'buried channel' descriptions provide superior descriptions of association rates, improving estimates by orders of magnitude.
authors.affiliation: Department of Pharmacology, University of California San Diego, La Jolla CA 92093.
authors.forename: P M
authors.initials: PM
authors.lastname: Kekenes-Huskey
authors.forename: A
authors.initials: A
authors.lastname: Gillette
authors.forename: J
authors.initials: J
authors.lastname: Hake
authors.forename: J A
authors.initials: JA
authors.lastname: McCammon