Stabilization of helix-turn-helix motif in short peptides

Effective De novo designing of proteins is a great challenge and a critical test of our knowledge of protein structure. The main problem is the attainment of a protein with a defined fold for its specific function. This paper reports the synthesis and characterization of a series of helix - turn - helix (h-t-h) peptides with stable secondary and tertiary structures. In the order to optimize the stability of the anti-parallel coiled-coil structure of alpha helical hairpin peptides, all peptides with the same interacting helical regions but different number and sequences of residues in the turn region was examined The turn region was incorporated between g and e(2) of leucine zipper heptad CD measurements showed that a four residue turn region was the best of stabilizing coiled coil structure in these peptides. The four residue turn sequence selected from h-t-h motifs of DNA binding proteins showed the highest helix stabilization in a short peptide of twenty nine amino acid residues.