Synthesis of unsymmetrical tweezer receptor libraries and identification of receptors for Lys-D-Ala-D-Ala in aqueous solution

Libraries of "unsymmetrical" tweezer receptors, featuring a guanidinium head group as a carboxylate binding site and two independently synthesized peptidic arms, have been prepared and screened to identify receptors for the N-Ac-Lys-D-Ala-D-Ala tri-peptide sequence. The binding properties of one such receptor structure, with dye-labeled N-Ac-LyS-D-Ala-D-Ala, were investigated. These studies demonstrated that when attached to the solid-phase, the receptor binds dye-labeled N-Ac-Lys-D-Ala-D-Ala, in buffered aqueous media, with mm binding affinity