SELF-ASSEMBLING PEPTIDE NANOTUBES

The general design criteria and synthesis of four new peptide-based so lid-state tubular array structures are described. Peptide nanotubes, w hich are extended tubular beta-sheet-like structures, are constructed by the self-assembly of flat, ring-shaped peptide subunits made up of alternating D- and L-amino acid residues. Peptide self-assembly is dir ected by the formation of an extensive network of intersubunit hydroge n bonds. In the crystal structures, nanotubes are stabilized by intert ubular hydrophobic packing interactions. Peptide nanotubes exhibit goo d mechanical and thermal stabilities in water and are stable for long periods of times in most common organic solvents including DMF and DMS O. The remarkable stability of peptide nanotubes can be attributed to the highly cooperative nature of the noncovalent interactions througho ut the crystal lattice. Nanotube structures were characterized by cryo electron microscopy, electron diffraction, Fourier-transform infrared spectroscopy, and crystal structure modeling. This study also serves t o exemplify the predictive structural aspects of the peptide self-asse mbly process.