Peptide bond mimicry by (E)-alkene and (Z)-fluoroalkene peptide isosteres: synthesis and bioevaluation of alpha-helical anti-HIV peptide analogues.

The alpha-helix structures of the anti-HIV fusion inhibitory peptides are stabilized by the amino acid sequence and by intrachain hydrogen bonds. The study of peptide analogues using (E)-alkene and (Z)-fluoroalkene dipeptide isosteres demonstrated the substantial, yet position-dependent, contribution of hydrogen bonds to the alpha-helix stability and anti-HIV bioactivity.