STRUCTURE AND PHARMACOLOGY OF PROTON-LINKED PEPTIDE TRANSPORTERS

The cellular uptake of small peptides such as di-, tri- and tetrapepti des and peptidomimetic drugs proceeds via specialized proton-coupled t ransporters (Refs. [1-6]). The cDNA clones encoding the oligopeptide t ransporters PepT1 and PepT2 were recently isolated and were found to c onstitute a new family of membrane transport proteins. These transport ers play important roles in tissues responsible for solute recovery su ch as epithelial cells of the small intestine and the proximal tubule of the kidney. New insights into the structure and pharmacology of the se transporters have been recently obtained based on studies involving Xenopus oocyte expression, electrophysiology and capillary electropho resis.