A quantitative structure-activity relationship for translocation of tripeptides via the human proton-coupled peptide transporter, hPEPT1 (SLC15A1).
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.
Omkvist
Diana Højmark
DH
Drug Transporters in ADME, Department of Pharmaceutics and Analytical Chemistry, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark.
Larsen
Simon Birksø
SB
Nielsen
Carsten Uhd
CU
Steffansen
Bente
B
Olsen
Lars
L
Jørgensen
Flemming Steen
FS
Brodin
Birger
B
D000818:Animals; D002460:Cell Line; D004285:Dogs; D006801:Humans; D008024:Ligands; D008564:Membrane Potentials; D009842:Oligopeptides / Q000378:metabolism*; D000074011:Peptide Transporter 1; D025341:Principal Component Analysis; D011522:Protons; D021281:Quantitative Structure-Activity Relationship; D013050:Spectrometry, Fluorescence; D027981:Symporters / Q000037:antagonists & inhibitors / Q000378:metabolism*
D008024:Ligands; D009842:Oligopeptides; D000074011:Peptide Transporter 1; D011522:Protons; C082186:SLC15A1 protein, human; D027981:Symporters
Eur J Biochem. 1999 Dec;266(2):502-8
10561591
Amino Acids. 2006 Sep;31(2):137-56
16868651
Mol Pharm. 2004 Mar-Apr;1(2):136-44
15832510
Biochem Biophys Res Commun. 1996 Mar 27;220(3):848-52
8607854
Clin Sci Mol Med. 1975 Oct;49(4):313-22
1192691
J Med Chem. 2006 Jun 15;49(12):3636-44
16759105
Gastroenterology. 2008 Jan;134(1):166-78
18061177
Expert Opin Drug Metab Toxicol. 2009 Aug;5(8):887-905
19519280
J Chem Inf Model. 2008 Jan;48(1):233-41
18092768
Biochemistry. 2001 Apr 10;40(14):4454-8
11284702
Biochem Pharmacol. 1984 Nov 1;33(21):3345-52
6497897
J Control Release. 2001 Sep 11;76(1-2):129-38
11532319
Am J Physiol Renal Physiol. 2000 Nov;279(5):F851-7
11053045
Eur J Pharm Sci. 2004 Dec;23(4-5):319-25
15567284
J Clin Pharmacol. 1999 Aug;39(8):800-4
10434231
Am J Physiol. 1995 Mar;268(3 Pt 2):F391-7
7900838
Eur J Pharm Sci. 2000 Oct;11 Suppl 2:S29-39
11033425
Eur J Pharm Sci. 2005 May;25(1):145-54
15854810
Biochem Biophys Res Commun. 1998 Sep 18;250(2):246-51
9753615
J Physiol. 1998 Nov 1;512 ( Pt 3):629-34
9882198
J Pharm Sci. 2000 Jun;89(6):781-9
10824137
J Clin Invest. 1971 Nov;50(11):2266-75
5096512
J Med Chem. 2005 Jun 30;48(13):4410-9
15974593
J Physiol. 2006 Jul 1;574(Pt 1):149-66
16627568
Nature. 1994 Apr 7;368(6471):563-6
8139693
Biochem Pharmacol. 1973 Dec 1;22(23):3099-108
4202581
ChemMedChem. 2008 Dec;3(12):1913-21
18979492
J Pharmacol Exp Ther. 1998 Sep;286(3):1166-70
9732374
Pharm Res. 2006 Mar;23(3):483-92
16489544
Chem Commun (Camb). 2006 Jan 21;(3):323-5
16391748
J Med Chem. 2003 Dec 18;46(26):5725-34
14667225