Sequence-Selective Binding of Peptides in Water by a Synthetic Receptor Molecule

摘要

Substantial progress has been made in recent years in the design and construction of synthetic receptors for small biological molecules including derivatives of simple amino acids and sugars. However, for synthetic receptors to be used in biological systems, it is necessary to design structures that bind biooligomers and biopolymers on the basis of their residue sequence in water. In this area, less progress has been made. Several hostlike structures have been found to bind peptides sequence selectively in organic solvents, but few examples of such binding in the more relevant aqueous environment have been reported. One readily available family of synthetic receptors that bind peptides sequence selectively in chloroform is based on polycyclic oligomers of trimesic acid (A(OH)_3) and 1,2-diamines (e.g., BH_2). One of these receptors, the D_2-symmetric 1, incorporates a large, hydrophobic binding cavity and in chloroform selectively binds certain amino acid sequences containing (L)Val. In this report, we describe the tetraam-monium ion 2, a water-soluble analog of 1, and show that it binds related amino acid sequences with high selectivity in water.