Poly-L-proline type II peptide mimics based on the 3-azabicyclo[3.1.0]hexane system

This paper describes conformational studies of proline-templated amino acids (PTAAs) based on the 3-azabicyclol[3.1.0]hexane system as well as conformational studies on short peptides composed of these PTAAs. NOE data, coupling constants, and molecular modeling are consistent with a flattened boat conformation for monomeric and oligomeric residues based on this bicyclic system. NMR studies on dimeric and trimeric oligomers are consistent with a populated poly-L-proline type II conformation in CDCl3 and D2O. Solution studies and molecular modeling predicts phi similar to -70 degrees, psi similar to 131 degrees, chi1 similar to -57 degrees, and chi2 similar to -158 degrees for oligomeric residues.