title: Water complexes of cytochrome P450: insights from energy decomposition analysis.
abstract: Water is a small molecule that nevertheless perturbs, sometimes significantly, the electronic properties of an enzyme's active site. In this study, interactions of a water molecule with the ferric heme and the compound I (Cpd I) intermediate of cytochrome P450 are studied. Energy decomposition analysis (EDA) schemes are used to investigate the physical origins of these interactions. Localized molecular orbital EDA (LMOEDA) implemented in the quantum chemistry software GAMESS and the EDA method implemented in the ADF quantum chemistry program are used. EDA reveals that the electrostatic and polarization effects act as the major driving force in both of these interactions. The hydrogen bonding in the Cpd I•••H₂O complex is similar to that in the water dimer; however, the relative importance of the electrostatic effect is somewhat larger in the water dimer.
authors.affiliation: Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore.
authors.forename: Nandun
authors.initials: N
authors.lastname: Thellamurege
authors.forename: Hajime
authors.initials: H
authors.lastname: Hirao
mesh_terms: D003577:Cytochrome P-450 Enzyme System / Q000737:chemistry*; D006860:Hydrogen Bonding; D008958:Models, Molecular; D008968:Molecular Conformation; D014867:Water / Q000737:chemistry*
chemical_list: D014867:Water; D003577:Cytochrome P-450 Enzyme System