W0048

DNA or Gramicidin Mimics – Double Helices Assembled from Synthetic Molecular Strands. Ivan Huc, IECB-Polytechnique, 16, Av. Pey Berland, 33607 Pessac Cedex, France.

A new family of oligomeric molecules spontaneously assemble into double helices mimicking the structures (and potentially the functions) of DNA and of Gramicidin A.

Whilst single helical conformations are common in synthetic and biopolymers, double-helical molecular motifs based on interstrand recognition remains an almost exclusive feature of nucleic acids and their analogs, and of polypeptides composed of amino acids with alternating L- and D-configurations such as gramicidin A. Very long pitch (> 30 nm) double or triple helices are also found in fibrous proteins such as keratin and collagen, and some synthetic polymers.

We present new oligomeric strands derived from 2,6-diaminopyridine and 2,6-pyridinedicarboxylic acid which undergo dynamic exchange between single and double helical molecular structures. The new double helical motif and the single helices were both characterized in the solid by single crystal X-ray diffraction analysis, and in solution by NMR.