RESUMO
This communication describes the folding propensity of a heterofoldamer motif featuring proline (Pro) and anthranilic acid (Ant) residues in a 1:2:1 (α:ß:α) constitutional ratio. Structural investigations unequivocally suggest that the hydrogen-bonding network of this foldamer motif can be switched between 9-membered and 6-membered by modulating the backbone chirality and constitutional ratio of the amino acid residues.
Assuntos
Prolina/química , ortoaminobenzoatos/química , Ligação de Hidrogênio , Modelos Moleculares , Estrutura MolecularRESUMO
This communication describes the development of conformationally constrained unnatural aromatic amino acids, constructed on rigid backbone wherein the carboxyl and amino groups project in two dimensions (planes) on the aromatic framework. Such a feature offers the possibility of design and development of conformationally ordered synthetic oligomers with intriguing structural architectures distinct from those classically observed. Furthermore, such amino acids will have the potential to extend the conformational space available for foldamer design with diverse backbone conformation and structural architectures.
Assuntos
Aminoácidos Aromáticos/química , Cristalografia por Raios X , Modelos Moleculares , Conformação MolecularRESUMO
Strikingly dissimilar hydrogen-bonding patterns have been observed for two sets of closely similar hetero foldamers containing carboxamide and sulfonamides at regular intervals. Although both foldamers maintain conformational ordering, the hydrogen-bonding pattern and backbone helical handedness differ diametrically.
Assuntos
Amidas/química , Peptídeos/síntese química , Sulfonamidas/química , Sequência de Aminoácidos , Aminoácidos/química , Cristalografia por Raios X , Ligação de Hidrogênio , Modelos Moleculares , Estrutura Molecular , Peptídeos/química , Estrutura Secundária de ProteínaRESUMO
Herein, we report on the folding pattern observed in a synthetic peptide featuring two highly mutually dependent, yet strikingly dissimilar, closed networks of hydrogen-bonded rings that work in a cumulative fashion to stabilize the entire folded architecture of the peptide. Structural studies unequivocally suggest that disruption of any one of these mutually-dependent hydrogen-bonded networks is deleterious to the stability of the fully folded conformation of the peptide.