TY - JOUR
T1 - Affinity and translocation relationships via hPEPT1 of H-Xaa-Ser-OH dipeptides
T2 - evaluation of H-Phe-Ser-OH as a pro-moiety for ibuprofen and benzoic acid prodrugs
AU - Omkvist, Diana Højmark
AU - Trangbæk, Dennis Jespersen
AU - Mildon, Jemma
AU - Paine, James Stephen
AU - Larsen, Birger Brodin
AU - Begtrup, Mikael
AU - Nielsen, Carsten Uhd
PY - 2011/2
Y1 - 2011/2
N2 - The intestinal di/tri-peptide transporter 1 (hPEPT1) has been suggested as a drug delivery target for peptide-based prodrugs. The aim of the study was to synthesize a series of 11 serine-containing dipeptides (H-Xaa-Ser-OH) and to investigate the relationship between binding to and transport via hPEPT1. An additional aim was to design a dipeptide which could serve as a pro-moiety for prodrugs targeted to hPEPT1. Xaa was chosen from the 20 proteogenic amino acids. The dipeptides were synthesized using solid phase peptide synthesis. The Ki-values of H-Xaa-Ser-OH dipeptides for hPEPT1 in MDCK/hPEPT1 cells ranged from 0.14 mM (log IC 50 = -0.85 ± 0.06) for H-Tyr-Ser-OH to 0.89 mM (log IC 50 = -0.09 ± 0.02) for H-Gly-Ser-OH, as measured in a competition assay with [14C]Gly-Sar. The dipeptides were translocated via hPEPT1 with Km-values in the range of 0.20 (log IC50 = -0.69 ± 0.04) for H-Met-Ser-OH to 1.04 (log IC50 = 0.02 ± 0.04) mM for H-Gly-Ser-OH. The relationship between ligand and transportate properties indicated that the initial binding of the ligand to hPEPT1 is the major determinant for translocation of the investigated dipeptides. H-Phe-Ser-OH was selected as a pro-moiety, and two prodrugs were synthesized, i.e. H-Phe-Ser(Ibuprofyl)-OH and H-Phe-Ser(Bz)-OH. Both H-Phe-Ser(Ibuprofyl)-OH and H-Phe-Ser(Bz)-OH had high affinity for hPEPT1 with Ki-values of 0.07 mM (log IC50 = -0.92 ± 0.12) and 0.12 mM (log IC50 = -1.17 ± 0.40), respectively. However, none of the prodrugs were translocated via hPEPT1. This indicated that the coupling of the drug compounds to the peptide backbone did not decrease transporter binding, but abolished translocation, and that high affinity of prodrugs does not necessarily translate into favourable permeation properties.
AB - The intestinal di/tri-peptide transporter 1 (hPEPT1) has been suggested as a drug delivery target for peptide-based prodrugs. The aim of the study was to synthesize a series of 11 serine-containing dipeptides (H-Xaa-Ser-OH) and to investigate the relationship between binding to and transport via hPEPT1. An additional aim was to design a dipeptide which could serve as a pro-moiety for prodrugs targeted to hPEPT1. Xaa was chosen from the 20 proteogenic amino acids. The dipeptides were synthesized using solid phase peptide synthesis. The Ki-values of H-Xaa-Ser-OH dipeptides for hPEPT1 in MDCK/hPEPT1 cells ranged from 0.14 mM (log IC 50 = -0.85 ± 0.06) for H-Tyr-Ser-OH to 0.89 mM (log IC 50 = -0.09 ± 0.02) for H-Gly-Ser-OH, as measured in a competition assay with [14C]Gly-Sar. The dipeptides were translocated via hPEPT1 with Km-values in the range of 0.20 (log IC50 = -0.69 ± 0.04) for H-Met-Ser-OH to 1.04 (log IC50 = 0.02 ± 0.04) mM for H-Gly-Ser-OH. The relationship between ligand and transportate properties indicated that the initial binding of the ligand to hPEPT1 is the major determinant for translocation of the investigated dipeptides. H-Phe-Ser-OH was selected as a pro-moiety, and two prodrugs were synthesized, i.e. H-Phe-Ser(Ibuprofyl)-OH and H-Phe-Ser(Bz)-OH. Both H-Phe-Ser(Ibuprofyl)-OH and H-Phe-Ser(Bz)-OH had high affinity for hPEPT1 with Ki-values of 0.07 mM (log IC50 = -0.92 ± 0.12) and 0.12 mM (log IC50 = -1.17 ± 0.40), respectively. However, none of the prodrugs were translocated via hPEPT1. This indicated that the coupling of the drug compounds to the peptide backbone did not decrease transporter binding, but abolished translocation, and that high affinity of prodrugs does not necessarily translate into favourable permeation properties.
KW - Former Faculty of Pharmaceutical Sciences
U2 - 10.1016/j.ejpb.2010.12.009
DO - 10.1016/j.ejpb.2010.12.009
M3 - Journal article
C2 - 21147219
SN - 0939-6411
VL - 77
SP - 327
EP - 331
JO - European Journal of Pharmaceutics and Biopharmaceutics
JF - European Journal of Pharmaceutics and Biopharmaceutics
IS - 2
ER -