... was inhibited not only byunlabeled Bip-Pro itself, but also by well known sub-strates of H+⁄ peptide cotransporters, such as Gly-Sar,Ala-Ala, Lys-Lys, Ala-Asp, d-Phe-Ala, Ala-Ala-Ala,d-aminolevulinic ... 5907Synthesis and characterization of a new and radiolabeledhigh-affinity substrate for H+/peptide cotransportersIlka Knu¨tter1, Bianka Hartrodt2,Ge´za To´th3, Attila Keresztes3, Gabor ... and conformation of recombinant membrane transporters[19], labeled substrates and inhibitors with a broadrange of affinity to the respective protein are alsoessential tools. In the course of...