Switching the H-bonding network of a foldamer by modulating the backbone chirality and constitutional ratio of amino acids

Abstract

This communication describes the folding propensity of a heterofoldamer motif featuring proline (Pro) and anthranilic acid (Ant) residues in a 1:2:1 (α:β: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.

Synthetic turn mimetics and hairpin nucleators: Quo Vadimus?

“…88 Other alterations, however, did seem to affect the structural assembly, such as amide to ester mutation at the C-terminus of the Ant-Pro turn, 89 substitution of another Ant residue at the N-terminus, 90 or replacement of an Ant unit with a fivemembered heterocycle-derived amino acid, 91 or constitutional ratio variation. 92 Constitutional variation of the residues brings about drastic changes in the conformational architecture of the peptide motifs occasionally.…”

“…88 Other alterations, however, did seem to affect the structural assembly, such as amide to ester mutation at the C-terminus of Ant-Pro turn, 89 substitution of another Ant residue at the N-terminus, 90 or replacement of Ant unit with fivemembered heterocycle-derived amino acid, 91 or constitutional ratio variation. 92 Constitutional variation of the residues brings about drastic changes in the conformational architecture of the peptide motifs occasionally. The typical case of synthetic zipper peptide motif formation with sequence αβ n (n=2, α = L/D Pro, β = Ant) is highly noteworthy in this regard, which could stabilize as large as 26 atoms-55 containing H-bonded network (Fig.…”