Abstract by Daniel Joaquin
Chemistry and Biochemistry
Impact of Dehydroamino Acids on the Structure and Stability of 3-10 Helical Peptides
A comparative study of the impact of small, medium-sized, and bulky dehydroamino acids (DAAs) on the structure and stability of Balaram’s incipient 310-helical peptide is reported. Replacement of the N-terminal Aib residue with a DAA afforded peptides that maintained the 310-helical shape in solution. In contrast, installation of a DAA in place of Aib-3 yielded peptides that preferred a beta-sheet-like conformation. The impact of the DAA on peptide structure was independent of size, with small (DAla), medium-sized (Z-DAbu), and bulky (DVal) DAAs exerting similar effects. The proteolytic stability of the contro peptide and its analogs was determined by incubation with Pronase. These results suggest that both bulky and the more synthetically accessible medium-sized DAAs should be valuable tools for bestowing rigidity and proteolytic stability on bioactive peptides.