Design, synthesis and study of photophysical/biophysical properties of small molecular scaffold peptides and fluorescent β-lactams

Abstract

This Thesis has a total of five chapters out of which the Chapter 1 is a literature review about the β-hairpin and β-sheet peptidomimetics. This review chapter contains a critical survey of conformationally constrained small molecular scaffold as inducer of particular secondary structure in a peptide, such as β-hairpin and β-sheet peptidomimetics. Chapter 2 includes uracil-di-aza-amino acid (UrAA) as a new family of molecular scaffold with ability to induce β-hairpin structure with H-bonded β-sheet conformation in a short peptide which is demostrated in two designed fluorescent pentapeptides. We established the dual mechanism of exciplex emission in ExcipFRET-peptide 2.61 containing donor-acceptor triazolyl unnatural fluorescent amino acids TMnapAlaDo and TPyAlaDo at N- and C- terminus respectively, forming a FRET pair. On the other hand fluorescent pentapeptide Excim-peptide 2.64 with triazolyl fluorescent unnatural amino acid TPyAlaDo at both the termini showed excimer emission in its β-sheet conformation. Both the peptides maintainning their predefined photophysics were found to interact with a model biomolecule BSA with fluorescence swith-on response. The exploration of sequence specific DNA binding event of UrAA scaffold and study of interaction with other protein biomolecules is the future prospect of this work.