Simulations of anion transport through OprP reveal the molecular basis for high affinity and selectivity for phosphate.

ABSTRACT: The outer membrane protein OprP from Pseudomonas aeruginosa forms a phosphate selective pore. To understand the mechanism of phosphate permeation and selectivity, we used three simulation techniques [equilibrium molecular dynamics simulations, steered molecular dynamics, and calculation of a potential of mean force (PMF)]. The PMF for phosphate reveals a deep free energy well midway along the OprP channel. Two adjacent phosphate-binding sites (W1 and W2), each with a well depth of approximately 8 kT, are identified close to the L3 loop in the most constricted region of the pore. A dissociation constant for phosphate of 6 microM is computed from the PMF, within the range of reported experimental values. The transfer of phosphate between sites W1 and W2 is correlated with changes in conforma

SUBMITTER: Pongprayoon P 

PROVIDER: S-EPMC2789165 | biostudies-literature | 2009 Dec

REPOSITORIES: biostudies-literature