The high dielectric constant of staphylococcal nuclease is encoded in its structural architecture.

ABSTRACT: The pK(a) values of Lys-66, Glu-66, and Asp-66 buried in the interior of the staphylococcal nuclease Δ+PHS variant were reported to be shifted by as much as 5 pK(a) units from their normal values. Reproducing the pK(a) of these buried ionizable residues using continuum electrostatic calculations required the use of a high protein dielectric constant of 10 or higher. The apparent high dielectric constant has been rationalized as a consequence of a local structural reorganization or increased fluctuations in the microenvironment of the mutation site (Chimenti, M. S., et al. J. Mol. Biol. 2011, 405, 361-377). We have calculated the dielectric constant of Δ+PHS and the Lys-66, Asp-66, and Glu-66 mutants from first principles using the Kirkwood-Fröhlich equation and discovered that staphylococc

SUBMITTER: Goh GB 

PROVIDER: S-EPMC3241862 | biostudies-literature | 2011 Dec

REPOSITORIES: biostudies-literature