Psi[CH(CF3)NH]Gly peptides, a conceptually new class of peptidomimetics having a stereogenictrifluoroethylamine group as a natural peptide-bond surrogate, have been synthesized by stereoselective addition of a-amino acid esters to trans-3,3,3-trifluoro-1-nitropropene. Long range nuclear Overhauser effects, detected via ROESY experiments, provided evidence that model W[CH(CF3)NH]Glytetrapeptides incorporating a trifluoroethylamine mimic of the dipeptide loop Pro-Gly can be represented by an ensemble of unfolded and folded conformations. The latter are driven by the formation of a hydrogen bond between a carbonyl group and the aminic proton of the trifluoroethylamine unit. MD calculations indicate a population of conformers which adopt folded b turn structures for all the L-peptides; on the other hand, a D-stereochemistry at the Pro residue induces a natural folding towards a b hairpin conformation driven by the formation of a second hydrogen bond, regardless of the stereochemistry of the stereogenic peptide bond surrogate.
Titolo: | Psi[CH(CF3)NH]Gly-peptides : synthesis and conformation analysis |
Autori: | BELLUCCI, MARIA CRISTINA (Secondo) |
Settore Scientifico Disciplinare: | Settore CHIM/06 - Chimica Organica |
Data di pubblicazione: | 7-apr-2009 |
Rivista: | |
Tipologia: | Article (author) |
Digital Object Identifier (DOI): | 10.1039/b901718f |
Appare nelle tipologie: | 01 - Articolo su periodico |