Synthesis of Peptidocalix[4]arene Libraries and Their Application to the Development of Chemical Sensors for Oligopeptides

Abstract

  Calix[4]arene libraries consisting of ca. 50000 members substituted with peptides at the lower rim were synthesized using encoded spilt synthesis with 15 amino acids. Screening of the library for binding with a dye-labeled oligopeptide indicated that some peptidocalix[4]arenes selectively bind the oligopeptide. The binding constant was estimated to be approximately 2×10⁴ mol dm^-3. In an attempt to develop chemical sensors for peptides, fluorescence-labeled peptidocalix[4]arene libraries consisting of ca. 3500 members were synthesized. The fluorescence spectrum of peptidocalix[4]arene, which was found in the screening of libraries against the target peptide, was dependent on the concentration of the peptide. The libraries substituted at the upper rim were also synthesized with the aim of developing more selective and sensitive chemical sensors. The binding selectivity of the library members for the target peptides was higher and the behavior of the sensing was markedly different from the lower rim-modified peptidocalixarene sensor.