Bioactive peptide-peptoid hybrids

The synthesis and characterization are reported of peptide-peptoid hybrids of [Thr(6)]-bradykinin and some opioid and antimicrobial peptides. The tyrosine, phenylalanine, valine and arginine residues were partially or total replaced by N-alkyl- glycine residues. The sub-monomer method was used to build N-substituted glycines during peptide elongation. Preliminary pharmacological experiments showed that replacement of a single amino acid residue may result in peptide-peptoid hybrids that retain selective and biomimetic agonistic activity. However multiple substitutions generally induce a more or less marked worsening of the peptide pharmacological properties.