Guest-Templated Selection and Amplification of a Receptor by Noncovalent Combinatorial Synthesis

A guest selects its own host by shifting the thermodynamic equilibrium in a mixture of possible receptors that all have a different affinity for the guest molecule. This evolutionary process can occur because the individual receptors interconvert through the reversible fomation of 36 cooperative hydrogen bonds. The picture shows schematically the favored receptor assembly.