Non-standard amino acids in peptide design and protein engineering

The introduction of non-coded amino acids with well defined stereochemical and functional properties will greatly enhance the scope of protein design and engineering. The present state of methodologies for incorporation of non-coded residues into proteins is examined. The prospects for conformationally constrained amino acid residues are evaluated in the light of peptide structural studies. Templates for secondary-structure nucleation and recent experiences in the incorporation of novel residues into proteins are considered.