Poisson-Boltzmann calculations of nonspecific salt effects on protein-protein binding free energies.

ABSTRACT: The salt dependence of the binding free energy of five protein-protein hetero-dimers and two homo-dimers/tetramers was calculated from numerical solutions to the Poisson-Boltzmann equation. Overall, the agreement with experimental values is very good. In all cases except one involving the highly charged lactoglobulin homo-dimer, increasing the salt concentration is found both experimentally and theoretically to decrease the binding affinity. To clarify the source of salt effects, the salt-dependent free energy of binding is partitioned into screening terms and to self-energy terms that involve the interaction of the charge distribution of a monomer with its own ion atmosphere. In six of the seven complexes studied, screening makes the largest contribution but self-energy effects can also b

SUBMITTER: Bertonati C 

PROVIDER: S-EPMC1861767 | biostudies-literature | 2007 Mar

REPOSITORIES: biostudies-literature