Semiempirical Quantum Mechanical Method PM6-DH2X Describes the Geometry and Energetics of CK2-Inhibitor Complexes Involving Halogen Bonds Well, While the Empirical Potential Fails
Petr Dobeš, Jan Řezáč, Jindřich Fanfrlík, Michal Otyepka, Pavel Hobza · The Journal of Physical Chemistry B · 2011
In the present study, we have investigated complexes of CK2 protein kinase with halogenated inhibitors by means of the advanced semiempirical quantum mechanical (SQM) PM6 method (called PM6-DH2X), which describes various types of noncovalent interactions including halogen bonding well. The PM6-DH2X method provides reliable geometries of those CK2 protein kinase-inhibitor complexes involving halogen bonds that agree well with the X-ray crystal structures. When the Amber empirical potential is applied, this agreement becomes considerably worse. Similarly, the binding free energies determined by the PM6-DH2X SQM method are much closer to the experimental inhibition constants than those based on the Amber empirical potential.