PepT1 - "Electrophysiological recordings of PepT1 (SLC15A1) activity on Nanion’s SURFE²R"
SURFE²R N1 application note: (0.9 MB)
The human peptide transporter PepT1 is an uptake transporter responsible for initial absorption and renal reabsorption of dietary oligopeptides. It is primarily located in the plasma membranes of enterocytes of the small intestine as well as the renal proximal tubular cells. PepT1 functions as a co-transporter, coupling the uphill peptide transport into the cells to the electrochemical proton gradient. Due to the movement of protons, PepT1 is an electrogenic transporter. PepT1 shows a very high capacity but a low affinity and substrate specificity. Its ability to transport a large range of compounds has enabled the rational design of drugs and pro-drugs (e.g. penicillins, ACE inhibitors) which have good oral bio-availability using delivery via PepT1. Designing pro-drugs with higher affinity for PepT1 is a successful strategy to increase the bio-availability of poorly absorbed drugs. Here we present electric real-time PepT1 activity measurements on the SURFE²R instruments using purified plasma membranes of CHO cells overexpressing PepT1. Peptide transport was activated on the SURFE²R N1 using a sensor with attached PepT1- containing membrane fragments which was inserted into the device. This was perfused with a buffer containing the dipeptide glycyl-glycine as the substrate. The data presented here show activation of PepT1 by glyclyglycine and inhibition by Lys[Z(No2)]-Val on the SURFE²R N1 and scale-up of the assay on the SURFE²R N96.