STABILIZATION OF HELIX-TURN-HELIX MOTIF IN SHORT PEPTIDES

Effective De novo designing of proteins is a great challenge and a cri tical test of our knowledge of protein structure. The main problem is the attainment of a protein with a defined fold for its specific funct ion. This paper reports the synthesis and characterization of a series of helix - turn - helix (h-t-h) peptides with stable secondary and te rtiary 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 numbe r and sequences of residues in the turn region was examined The turn r egion was incorporated between g and e(2) of leucine zipper heptad CD measurements showed that a four residue turn region was the best of st abilizing coiled coil structure in these peptides. The four residue tu rn sequence selected from h-t-h motifs of DNA binding proteins showed the highest helix stabilization in a short peptide of twenty nine amin o acid residues.