title: Model based on GRID-derived descriptors for estimating CYP3A4 enzyme stability of potential drug candidates.
abstract: A number of computational approaches are being proposed for an early optimization of ADME (absorption, distribution, metabolism and excretion) properties to increase the success rate in drug discovery. The present study describes the development of an in silico model able to estimate, from the three-dimensional structure of a molecule, the stability of a compound with respect to the human cytochrome P450 (CYP) 3A4 enzyme activity. Stability data were obtained by measuring the amount of unchanged compound remaining after a standardized incubation with human cDNA-expressed CYP3A4. The computational method transforms the three-dimensional molecular interaction fields (MIFs) generated from the molecular structure into descriptors (VolSurf and Almond procedures). The descriptors were correlated to the experimental metabolic stability classes by a partial least squares discriminant procedure. The model was trained using a set of 1800 compounds from the Pharmacia collection and was validated using two test sets: the first one including 825 compounds from the Pharmacia collection and the second one consisting of 20 known drugs. This model correctly predicted 75% of the first and 85% of the second test set and showed a precision above 86% to correctly select metabolically stable compounds. The model appears a valuable tool in the design of virtual libraries to bias the selection toward more stable compounds.
authors.affiliation: Pharmacokinetics, Dynamics and Metabolism, Gruppo Pfizer Inc., Viale Pasteur 10, I-20014 Nerviano (Mi), Italy. Patrizia.Crivori@Pharmacia.com
authors.forename: Patrizia
authors.initials: P
authors.lastname: Crivori
authors.forename: Ismael
authors.initials: I
authors.lastname: Zamora
authors.forename: Bill
authors.initials: B
authors.lastname: Speed
authors.forename: Christian
authors.initials: C
authors.lastname: Orrenius
authors.forename: Italo
authors.initials: I
authors.lastname: Poggesi
mesh_terms: D051544:Cytochrome P-450 CYP3A; D003577:Cytochrome P-450 Enzyme System / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D004247:DNA; D004795:Enzyme Stability; D006801:Humans; D004364:Pharmaceutical Preparations
chemical_list: D004364:Pharmaceutical Preparations; D004247:DNA; D003577:Cytochrome P-450 Enzyme System; C104464:CYP3A protein, human; D051544:Cytochrome P-450 CYP3A; C510163:CYP3A4 protein, human