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Sun L, Meng S. Structure-based model profiles affinity constant of drugs with hPEPT1 for rapid virtual screening of hPEPT1's substrate. SAR AND QSAR IN ENVIRONMENTAL RESEARCH 2016; 27:637-652. [PMID: 27586363 DOI: 10.1080/1062936x.2016.1216010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2016] [Accepted: 07/19/2016] [Indexed: 06/06/2023]
Abstract
The human proton-coupled peptide transporter (hPEPT1) with broad substrates is an important route for improving the pharmacokinetic performance of drugs. Thus, it is essential to predict the affinity constant between drug molecule and hPEPT1 for rapid virtual screening of hPEPT1's substrate during lead optimization, candidate selection and hPEPT1 prodrug design. Here, a structure-based in silico model for 114 compounds was constructed based on eight structural parameters. This model was built by the multiple linear regression method and satisfied all the prerequisites of the regression models. For the entire data set, the r(2) and adjusted r(2) values were 0.74 and 0.72, respectively. Then, this model was used to perform substrate/non-substrate classification. For 29 drugs from DrugBank database, all were correctly classified as substrates of hPEPT1. This model was also used to perform substrate/non-substrate classification for 18 drugs and their prodrugs; this QSAR model also can distinguish between the substrate and non-substrate. In conclusion, the QSAR model in this paper was validated by a large external data set, and all results indicated that the developed model was robust, stable, and can be used for rapid virtual screening of hPEPT1's substrate in the early stage of drug discovery.
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Affiliation(s)
- L Sun
- a Department of Pharmaceutics , School of Pharmacy, China Medical University , Shenyang , Liaoning , P.R. China
| | - S Meng
- a Department of Pharmaceutics , School of Pharmacy, China Medical University , Shenyang , Liaoning , P.R. China
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Cherkasov A, Muratov EN, Fourches D, Varnek A, Baskin II, Cronin M, Dearden J, Gramatica P, Martin YC, Todeschini R, Consonni V, Kuz'min VE, Cramer R, Benigni R, Yang C, Rathman J, Terfloth L, Gasteiger J, Richard A, Tropsha A. QSAR modeling: where have you been? Where are you going to? J Med Chem 2014; 57:4977-5010. [PMID: 24351051 PMCID: PMC4074254 DOI: 10.1021/jm4004285] [Citation(s) in RCA: 1040] [Impact Index Per Article: 104.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Quantitative structure-activity relationship modeling is one of the major computational tools employed in medicinal chemistry. However, throughout its entire history it has drawn both praise and criticism concerning its reliability, limitations, successes, and failures. In this paper, we discuss (i) the development and evolution of QSAR; (ii) the current trends, unsolved problems, and pressing challenges; and (iii) several novel and emerging applications of QSAR modeling. Throughout this discussion, we provide guidelines for QSAR development, validation, and application, which are summarized in best practices for building rigorously validated and externally predictive QSAR models. We hope that this Perspective will help communications between computational and experimental chemists toward collaborative development and use of QSAR models. We also believe that the guidelines presented here will help journal editors and reviewers apply more stringent scientific standards to manuscripts reporting new QSAR studies, as well as encourage the use of high quality, validated QSARs for regulatory decision making.
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Affiliation(s)
- Artem Cherkasov
- Vancouver Prostate Centre, University of British Columbia, Vancouver, BC, V6H3Z6, Canada
| | - Eugene N. Muratov
- Laboratory for Molecular Modeling, UNC Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, 27599, USA
- Department of Molecular Structure and Cheminformatics, A.V. Bogatsky Physical-Chemical Institute National Academy of Sciences of Ukraine, Odessa, 65080, Ukraine
| | - Denis Fourches
- Laboratory for Molecular Modeling, UNC Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Alexandre Varnek
- Department of Chemistry, L. Pasteur University of Strasbourg, Strasbourg, 67000, France
| | - Igor I. Baskin
- Department of Physics, Lomonosov Moscow State University, Moscow, 119991, Russia
| | - Mark Cronin
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Liverpool L33AF, UK
| | - John Dearden
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Liverpool L33AF, UK
| | - Paola Gramatica
- Department of Structural and Functional Biology, University of Insubria, Varese, 21100, Italy
| | | | - Roberto Todeschini
- Milano Chemometrics and QSAR Research Group, University of Milano-Bicocca, Milan, 20126, Italy
| | - Viviana Consonni
- Milano Chemometrics and QSAR Research Group, University of Milano-Bicocca, Milan, 20126, Italy
| | - Victor E. Kuz'min
- Department of Molecular Structure and Cheminformatics, A.V. Bogatsky Physical-Chemical Institute National Academy of Sciences of Ukraine, Odessa, 65080, Ukraine
| | | | - Romualdo Benigni
- Environment and Health Department, Istituto Superiore di Sanita’, Rome, 00161, Italy
| | | | - James Rathman
- Altamira LLC, Columbus OH 43235, USA
- Department of Chemical and Biomolecular Engineering, the Ohio State University, Columbus, OH 43215, USA
| | | | | | - Ann Richard
- National Center for Computational Toxicology, U.S. Environmental Protection Agency, Research Triangle Park, NC, 27519, USA
| | - Alexander Tropsha
- Laboratory for Molecular Modeling, UNC Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, 27599, USA
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Kottra G, Spanier B, Verri T, Daniel H. Peptide transporter isoforms are discriminated by the fluorophore-conjugated dipeptides β-Ala- and d-Ala-Lys-N-7-amino-4-methylcoumarin-3-acetic acid. Physiol Rep 2013; 1:e00165. [PMID: 24744852 PMCID: PMC3970736 DOI: 10.1002/phy2.165] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Revised: 09/16/2013] [Accepted: 10/26/2013] [Indexed: 02/06/2023] Open
Abstract
Peptide transporters of the SLC15 family are classified by structure and function into PEPT1 (low‐affinity/high‐capacity) and PEPT2 (high‐affinity/low‐capacity) isoforms. Despite the differences in kinetics, both transporter isoforms are reckoned to transport essentially all possible di‐ and tripeptides. We here report that the fluorophore‐conjugated dipeptide derivatives β‐Ala‐Lys‐N‐7‐amino‐4‐methylcoumarin‐3‐acetic acid (β‐AK‐AMCA) and d‐Ala‐Lys‐N‐7‐amino‐4‐methylcoumarin‐3‐acetic acid (d‐AK‐AMCA) are transported by distinct PEPT isoforms in a species‐specific manner. Transport of the fluorophore peptides was studied (1) in vitro after heterologous expression in Xenopus oocytes of PEPT1 and PEPT2 isoforms from different vertebrate species and of PEPT1 and PEPT2 transporters from Caenorhabditis elegans by using electrophysiological and fluorescence methods and (2) in vivo in C. elegans by using fluorescence methods. Our results indicate that both substrates are transported by the vertebrate “renal‐type” and the C. elegans “intestinal‐type” peptide transporter only. A systematic analysis among species finds four predicted amino acid residues along the sequence that may account for the substrate uptake differences observed between the vertebrate PEPT1/nematode PEPT2 and the vertebrate PEPT2/nematode PEPT1 subtype. This selectivity on basis of isoforms and species may be helpful in better defining the structure–function determinants of the proteins of the SLC15 family. Peptide transporters of the SLC15 family can be classified by structure and function into the PEPT1 (low‐affinity/high‐capacity) and PEPT2 (high‐affinity/low‐capacity) phenotype. We found that the fluorophore‐conjugated dipeptide derivatives β‐Ala‐Lys‐N‐7‐amino‐4‐methylcoumarin‐3‐acetic acid (β‐AK‐AMCA) and d‐Ala‐Lys‐N‐7‐amino‐4‐methylcoumarin‐3‐acetic acid (d‐AK‐AMCA) are transported only by distinct PEPT isoforms in a species‐specific manner. This selectivity on basis of isoforms and species should be helpful in further defining the substrate‐binding domain of peptide transporters.
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Affiliation(s)
- Gabor Kottra
- ZIEL Research Center of Nutrition and Food Sciences, Abteilung Biochemie, Technische Universität München, Gregor-Mendel-Str. 2, Freising, D-85350, Germany
| | - Britta Spanier
- ZIEL Research Center of Nutrition and Food Sciences, Abteilung Biochemie, Technische Universität München, Gregor-Mendel-Str. 2, Freising, D-85350, Germany
| | - Tiziano Verri
- Laboratory of General Physiology, Department of Biological and Environmental Sciences and Technologies, University of Salento, via Provinciale Lecce-Monteroni, Lecce, I-73100, Italy
| | - Hannelore Daniel
- ZIEL Research Center of Nutrition and Food Sciences, Abteilung Biochemie, Technische Universität München, Gregor-Mendel-Str. 2, Freising, D-85350, Germany
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Polishchuk PG, Kuz'min VE, Artemenko AG, Muratov EN. Universal Approach for Structural Interpretation of QSAR/QSPR Models. Mol Inform 2013; 32:843-53. [DOI: 10.1002/minf.201300029] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2013] [Accepted: 07/29/2013] [Indexed: 11/07/2022]
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Krylov IS, Kashemirov BA, Hilfinger JM, McKenna CE. Evolution of an amino acid based prodrug approach: stay tuned. Mol Pharm 2013; 10:445-58. [PMID: 23339402 PMCID: PMC3788118 DOI: 10.1021/mp300663j] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Certain acyclic nucleoside phosphonates (ANPs) such as (S)-HPMPC (cidofovir, Vistide) and (S)-HPMPA have been shown to be active against a broad spectrum of DNA and retroviruses. However, their poor absorption as well as their toxicity limit the utilization of these therapeutics in the clinic. Nucleoside phosphonates are poorly absorbed primarily due to the presence of the phosphonic acid group, which ionizes at physiological pH. When dosed intravenously they display dose-limiting nephrotoxicity due to their accumulation in the kidney. To overcome these limitations, nucleoside phosphonate prodrug strategies have taken center stage in the development pathway and a number of different approaches are at various stages of development. Our efforts have focused on the development of ANP prodrugs in which a benign amino acid promoiety masks a phosphonate P-OH via a hydroxyl side chain. The design of these prodrugs incorporates multiple chemical groups (the P-X-C linkage, the amino acid stereochemistry, the C-terminal and N-terminal functional groups) that can be tuned to modify absorption, pharmacokinetic and efficacy properties with the goal of improving overall prodrug performance.
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Affiliation(s)
- Ivan S. Krylov
- Department of Chemistry, University of Southern California, Los Angeles, CA 90089-0744 USA
| | - Boris A. Kashemirov
- Department of Chemistry, University of Southern California, Los Angeles, CA 90089-0744 USA
| | | | - Charles E. McKenna
- Department of Chemistry, University of Southern California, Los Angeles, CA 90089-0744 USA
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Saaby L, Nielsen C, Steffansen B, Larsen S, Brodin B. Current status of rational design of prodrugs targeting the intestinal di/tri-peptide transporter hPEPT1 (SLC15A1). J Drug Deliv Sci Technol 2013. [DOI: 10.1016/s1773-2247(13)50047-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Sedykh A, Fourches D, Duan J, Hucke O, Garneau M, Zhu H, Bonneau P, Tropsha A. Human intestinal transporter database: QSAR modeling and virtual profiling of drug uptake, efflux and interactions. Pharm Res 2012; 30:996-1007. [PMID: 23269503 DOI: 10.1007/s11095-012-0935-x] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2012] [Accepted: 11/11/2012] [Indexed: 02/08/2023]
Abstract
PURPOSE Membrane transporters mediate many biological effects of chemicals and play a major role in pharmacokinetics and drug resistance. The selection of viable drug candidates among biologically active compounds requires the assessment of their transporter interaction profiles. METHODS Using public sources, we have assembled and curated the largest, to our knowledge, human intestinal transporter database (>5,000 interaction entries for >3,700 molecules). This data was used to develop thoroughly validated classification Quantitative Structure-Activity Relationship (QSAR) models of transport and/or inhibition of several major transporters including MDR1, BCRP, MRP1-4, PEPT1, ASBT, OATP2B1, OCT1, and MCT1. RESULTS QSAR models have been developed with advanced machine learning techniques such as Support Vector Machines, Random Forest, and k Nearest Neighbors using Dragon and MOE chemical descriptors. These models afforded high external prediction accuracies of 71-100% estimated by 5-fold external validation, and showed hit retrieval rates with up to 20-fold enrichment in the virtual screening of DrugBank compounds. CONCLUSIONS The compendium of predictive QSAR models developed in this study can be used for virtual profiling of drug candidates and/or environmental agents with the optimal transporter profiles.
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Affiliation(s)
- Alexander Sedykh
- Laboratory for Molecular Modeling Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina 100K Beard Hall, Chapel Hill, North Carolina, 27599-7568, USA
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Hasegawa K, Funatsu K. Evolution of PLS for Modeling SAR and omics Data. Mol Inform 2012; 31:766-75. [DOI: 10.1002/minf.201200090] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2012] [Accepted: 10/15/2012] [Indexed: 11/06/2022]
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Peterson LW, Sala-Rabanal M, Krylov IS, Serpi M, Kashemirov BA, McKenna CE. Serine side chain-linked peptidomimetic conjugates of cyclic HPMPC and HPMPA: synthesis and interaction with hPEPT1. Mol Pharm 2010; 7:2349-61. [PMID: 20929265 DOI: 10.1021/mp100186b] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Cidofovir (HPMPC), a broad spectrum antiviral agent, cannot be administered orally due to ionization of its phosphonic acid group at physiological pH. One prodrug approach involves conversion to the cyclic form (cHPMPC, 1) and esterification by the side chain hydroxyl group of a peptidomimetic serine. Transport studies in a rat model have shown enhanced levels of total cidofovir species in the plasma after oral dosing with L-Val-L-Ser-OMe cHPMPC, 2a. To explore the possibility that 2a and its three L/D stereoisomers 2b-d undergo active transport mediated by the peptide-specific intestinal transporter PEPT1, we performed radiotracer uptake and electrophysiology experiments applying the two-electrode voltage clamp technique in Xenopus laevis oocytes overexpressing human PEPT1 (hPEPT1, SLC15A1). 2a-d did not induce inward currents, indicating that they are not transported, but the stereoisomers with an L-configuration at the N-terminal valine (2a and 2b) potently inhibited transport of the hPEPT1 substrate glycylsarcosine (Gly-Sar). A "reversed" dipeptide conjugate, L-Ser-L-Ala-OiPr cHPMPC (4), also did not exhibit detectable transport, but completely abolished the Gly-Sar signal, suggesting that affinity of the transporter for these prodrugs is not impaired by a proximate linkage to the drug in the N-terminal amino acid of the dipeptide. Single amino acid conjugates of cHPMPC (3a and 3b) or cHPMPA (5, 6a and 6b) were not transported and only weakly inhibited Gly-Sar transport. The known hPEPT1 prodrug substrate valacyclovir (7) and its L-Val-L-Val dipeptide analogue (8) were used to verify coupled transport by the oocyte model. The results indicate that the previously observed enhanced oral bioavailability of 2a relative to the parent drug is unlikely to be due to active transport by hPEPT1. Syntheses of the novel compounds 2b-d and 3-6 are described, including a convenient solid-phase method to prepare 5, 6a and 6b.
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Affiliation(s)
- Larryn W Peterson
- Department of Chemistry, University of Southern California, Los Angeles, California 90089-0744, USA
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Wang CL, Fan YB, Lu HH, Tsai TH, Tsai MC, Wang HP. Evidence of D-phenylglycine as delivering tool for improving L-dopa absorption. J Biomed Sci 2010; 17:71. [PMID: 20815935 PMCID: PMC2941486 DOI: 10.1186/1423-0127-17-71] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2010] [Accepted: 09/06/2010] [Indexed: 11/10/2022] Open
Abstract
Background l-Dopa has been used for Parkinson's disease management for a long time. However, its wide variety in the rate and the extent of absorption remained challenge in designing suitable therapeutic regime. We report here a design of using d-phenylglycine to guard l-dopa for better absorption in the intestine via intestinal peptide transporter I (PepT1). Methods d-Phenylglycine was chemically attached on l-dopa to form d-phenylglycine-l-dopa as a dipeptide prodrug of l-dopa. The cross-membrane transport of this dipeptide and l-dopa via PepT1 was compared in brush-boarder membrane vesicle (BBMV) prepared from rat intestine. The intestinal absorption was compared by in situ jejunal perfusion in rats. The pharmacokinetics after i.v. and p.o. administration of both compounds were also compared in Wistar rats. The striatal dopamine released after i.v. administration of d-phenylglycine-l-dopa was collected by brain microdialysis and monitored by HPLC. Anti-Parkinsonism effect was determined by counting the rotation of 6-OHDA-treated unilateral striatal lesioned rats elicited rotation with (+)-methamphetamine (MA). Results The BBMV uptake of d-phenylglycine-l-dopa was inhibited by Gly-Pro, Gly-Phe and cephradine, the typical PepT1 substrates, but not by amino acids Phe or l-dopa. The cross-membrane permeability (Pm*) determined in rat jejunal perfusion of d-phenylglycine-l-dopa was higher than that of l-dopa (2.58 ± 0.14 vs. 0.94 ± 0.10). The oral bioavailability of d-phenylglycine-l-dopa was 31.7 times higher than that of l-dopa in rats. A sustained releasing profile of striatal dopamine was demonstrated after i. v. injection of d-phenylglycine-l-dopa (50 mg/kg), indicated that d-phenylglycine-l-dopa might be a prodrug of dopamine. d-Phenylglycine-l-dopa was more efficient than l-dopa in lowering the rotation of unilateral striatal lesioned rats (19.1 ± 1.7% vs. 9.9 ± 1.4%). Conclusion The BBMV uptake studies indicated that d-phenylglycine facilitated the transport of l-dopa through the intestinal PepT1 transporter. The higher jejunal permeability and the improved systemic bioavailability of d-phenylglycine-l-dopa in comparison to that of l-dopa suggested that d-phenylglycine is an effective delivery tool for improving the oral absorption of drugs like l-dopa with unsatisfactory pharmacokinetics. The gradual release of dopamine in brain striatum rendered this dipeptide as a potential dopamine sustained-releasing prodrug.
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Affiliation(s)
- Chun-Li Wang
- Taipei Medical University College of Pharmacy, 250 Wu-Hsing St,, Taipei, 110-31, Taiwan
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Omkvist DH, Larsen SB, Nielsen CU, Steffansen B, Olsen L, Jørgensen FS, Brodin B. A quantitative structure-activity relationship for translocation of tripeptides via the human proton-coupled peptide transporter, hPEPT1 (SLC15A1). AAPS JOURNAL 2010; 12:385-96. [PMID: 20449699 DOI: 10.1208/s12248-010-9195-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2010] [Accepted: 04/09/2010] [Indexed: 11/30/2022]
Abstract
The human intestinal proton-coupled peptide transporter, hPEPT1 (SLC15A1), has been identified as an absorptive transporter for both drug substances and prodrugs. An understanding of the prerequisites for transport has so far been obtained from models based on competition experiments. These models have limited value for predicting substrate translocation via hPEPT1. The aim of the present study was to investigate the requirements for translocation via hPEPT1. A set of 55 tripeptides was selected from a principal component analysis based on VolSurf descriptors using a statistical design. The majority of theses tripeptides have not previously been investigated. Translocation of the tripeptides via hPEPT1 was determined in a MDCK/hPEPT1 cell-based translocation assay measuring substrate-induced changes in fluorescence of a membrane potential-sensitive probe. Affinities for hPEPT1 of relevant tripeptides were determined by competition studies with [14C]Gly-Sar in MDCK/hPEPT1 cells. Forty tripeptides were found to be substrates for hPEPT1, having K(m)(app) values in the range 0.4-28 mM. Eight tripeptides were not able to cause a substrate-induced change in fluorescence in the translocation assay and seven tripeptides interacted with the probe itself. The conformationally restricted tripeptide Met-Pro-Pro was identified as a novel high-affinity inhibitor of hPEPT1. We also discovered the first tripeptide (Asp-Ile-Arg) that was neither a substrate nor an inhibitor of hPEPT1. To rationalise the requirements for transport, a quantitative structure-activity relationship model correlating K(m)(app) values with VolSurf descriptors was constructed. This is, to our knowledge, the first predictive model for the translocation of tripeptides via hPEPT1.
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Affiliation(s)
- Diana Højmark Omkvist
- Drug Transporters in ADME, Department of Pharmaceutics and Analytical Chemistry, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
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12
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Larsen SB, Omkvist DH, Brodin B, Nielsen CU, Steffansen B, Olsen L, Jørgensen FS. Discovery of ligands for the human intestinal Di-/Tripeptide transporter (hPEPT1) using a QSAR-assisted virtual screening strategy. ChemMedChem 2009; 4:1439-45. [PMID: 19557803 DOI: 10.1002/cmdc.200900145] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The discovery of novel ligands for the hPEPT1 transporter is reported. By exploiting a fast and rigorously validated QSAR model in combination with the distance in activity-centered chemical space (DACCS) approach, a database of commercially available compounds (Sigma-Aldrich) was screened for virtual hits. Twelve compounds were then purchased and characterized in an apical [14C]Gly-Sar uptake competition assay. Four compounds displayed affinity in the medium-to-high range. A simple benzophenone derivative displayed high affinity with a sub-millimolar binding constant (Ki=0.24 mM). The results of this study will serve as starting points for future projects, including the design and synthesis of compound libraries that seek to systematically explore the fundamental requirements for binding and transport by hPEPT1.
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Affiliation(s)
- Simon Birksø Larsen
- Department of Medicinal Chemistry, Faculty of Pharmaceutical Sciences, University of Copenhagen, 2 Universitetsparken, 2100 Copenhagen, Denmark
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Puratchikody A, Doble M. QSAR Studies on Antiepileptic and Locomotorin vivoActivities of 4,5-diphenyl-1H-Imidazoles. Chem Biol Drug Des 2009; 74:173-82. [DOI: 10.1111/j.1747-0285.2009.00837.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Pedretti A, De Luca L, Marconi C, Negrisoli G, Aldini G, Vistoli G. Modeling of the intestinal peptide transporter hPepT1 and analysis of its transport capacities by docking and pharmacophore mapping. ChemMedChem 2009; 3:1913-21. [PMID: 18979492 DOI: 10.1002/cmdc.200800184] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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.
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Affiliation(s)
- Alessandro Pedretti
- Istituto di Chimica Farmaceutica e Tossicologica "Pietro Pratesi", Facoltà di Farmacia, Università degli Studi di Milano, Via Mangiagalli 25, 20133 Milano, Italy
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