Identification of sequence selective receptors for peptides with a carboxylic acid terminus

Split-and-mix libraries of resin-bound "tweezer" receptors have been prepar ed and screened to identify receptors for dye-labelled tripeptides. The rec eptors incorporate a diamidopyridine unit to serve as a specific recognitio n site for the CO2H group, leading to strong and selective receptors for pe ptide guests with a CO2H terminus. The role of the dye-label, attached to t he peptide guest to allow visualisation of selective recognition events in the screening experiments, has also been examined and was found to have a s ignificant influence on the binding selectivities.