TY - JOUR
T1 - Ligand binding analyses of the putative peptide transporter YjdL from E. coli display a significant selectivity towards dipeptides
AU - Ernst, Heidi Asschenfeldt
AU - Pham, Antony
AU - Hald, Helle
AU - Kastrup, Jette Sandholm
AU - Rahman, Moazur
AU - Mirza, Osman Asghar
N1 - Keywords: E. coli; POTs; Transport; Peptides; Ligand specificity; YjdL
PY - 2009
Y1 - 2009
N2 - Proton-dependent oligopeptide transporters (POTs) are secondary active transporters that couple the inwards translocation of di- and tripeptides to inwards proton translocation. Escherichia coli contains four genes encoding the putative POT proteins YhiP, YdgR, YjdL and YbgH. We have over-expressed the previously uncharacterized YjdL and investigated the peptide specificity by means of uptake inhibition. The IC(50) value for the dipeptide Ala-Ala was measured to 22mM while Ala-Ala-Ala was not able to inhibit uptake. In addition, IC(50) values of 0.3mM and 1.5mM were observed for Ala-Lys and Tyr-Ala, respectively, while the alanyl-extended tripeptides Ala-Lys-Ala, Ala-Ala-Lys, Ala-Tyr-Ala and Tyr-Ala-Ala displayed values of 8, >50, 31 and 31mM, respectively. These results clearly indicate that unlike most POT members characterized to date, including YdgR and YhiP, YjdL shows significantly higher specificity towards dipeptides.
AB - Proton-dependent oligopeptide transporters (POTs) are secondary active transporters that couple the inwards translocation of di- and tripeptides to inwards proton translocation. Escherichia coli contains four genes encoding the putative POT proteins YhiP, YdgR, YjdL and YbgH. We have over-expressed the previously uncharacterized YjdL and investigated the peptide specificity by means of uptake inhibition. The IC(50) value for the dipeptide Ala-Ala was measured to 22mM while Ala-Ala-Ala was not able to inhibit uptake. In addition, IC(50) values of 0.3mM and 1.5mM were observed for Ala-Lys and Tyr-Ala, respectively, while the alanyl-extended tripeptides Ala-Lys-Ala, Ala-Ala-Lys, Ala-Tyr-Ala and Tyr-Ala-Ala displayed values of 8, >50, 31 and 31mM, respectively. These results clearly indicate that unlike most POT members characterized to date, including YdgR and YhiP, YjdL shows significantly higher specificity towards dipeptides.
KW - Former Faculty of Pharmaceutical Sciences
U2 - 10.1016/j.bbrc.2009.08.098
DO - 10.1016/j.bbrc.2009.08.098
M3 - Journal article
C2 - 19703419
SN - 0006-291X
VL - 389
SP - 112
EP - 116
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
IS - 1
ER -