title: Modeling of the intestinal peptide transporter hPepT1 and analysis of its transport capacities by docking and pharmacophore mapping.
abstract: An early pharmacokinetic screen for peptidomimetic drugs should have the ability to predict molecules with high affinity for intestinal transporters, as peptide-like derivatives are seldom absorbed passively. Hence, the first objective of this study was to generate a reliable model for the structure of the hPepT1 protein, which is the main intestinal transporter involved in the absorption of both dietary peptides and peptidomimetics. The modeling was based on the resolved structure of the homologous bacterial lactose permease LacY using a fragmental strategy. The interaction capacities of the hPepT1 model were explored by docking a set of 50 known ligands. Despite the known predilection of hPepT1 for hydrophobic ligands, docking results unveiled the key role of the polar interactions stabilized by charged termini, especially concerning the ammonium head group. The docking results were further verified by developing a pharmacophore model that confirmed the key features required for optimal hPepT1 affinity. The consistency of the docking results and the agreement with the pharmacophore model afford an encouraging validation for the proposed model and suggest that it can be exploited to design peptide-like molecules with an improved affinity for such a transporter.
authors.affiliation: Istituto di Chimica Farmaceutica e Tossicologica "Pietro Pratesi", Facoltà di Farmacia, Università degli Studi di Milano, Via Mangiagalli 25, 20133 Milano, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Pedretti
authors.forename: Laura
authors.initials: L
authors.lastname: De Luca
authors.forename: Cristina
authors.initials: C
authors.lastname: Marconi
authors.forename: Gianpaolo
authors.initials: G
authors.lastname: Negrisoli
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Aldini
authors.forename: Giulio
authors.initials: G
authors.lastname: Vistoli
mesh_terms: D001692:Biological Transport; D003198:Computer Simulation; D016208:Databases, Factual; D015195:Drug Design; D006801:Humans; D021621:Imaging, Three-Dimensional; D008958:Models, Molecular; D008968:Molecular Conformation; D000074011:Peptide Transporter 1; D010455:Peptides / Q000378:metabolism; D013329:Structure-Activity Relationship; D027981:Symporters / Q000737:chemistry* / Q000494:pharmacology
chemical_list: D000074011:Peptide Transporter 1; D010455:Peptides; C082186:SLC15A1 protein, human; D027981:Symporters