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Updated: Jul 18, 2026

Construction and Systematical Symmetric Studies of a Series of Supramolecular Clusters with Binary or Ternary Ammonium Triphenylacetates
Published on: February 15, 2016
A reverse turn structure induced by a D,L-alpha-aminoxy acid dimer.
1Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, P.R. China. yangdan@hku.hk
Linear peptides with D,L-alpha-aminoxy acid dimers form novel loop and reverse turn structures. These findings advance peptide design by enabling specific conformational constraints.
Area of Science:
- Peptide Chemistry
- Structural Biology
- Organic Chemistry
Background:
- Previous research demonstrated D-alpha-aminoxy acids form homochiral N-O turns, yielding helical structures.
- Linear peptides incorporating D,L-alpha-aminoxy acid dimers were investigated for novel conformational properties.
Purpose of the Study:
- To explore the conformational behavior of linear peptides containing a D,L-alpha-aminoxy acid dimer segment.
- To investigate the potential of these segments in constraining peptide secondary structures, specifically reverse turns.
Main Methods:
- Nuclear Magnetic Resonance (NMR) spectroscopy (1D, 2D-NOESY, dilution studies).
- X-ray crystallography.
- Quantum mechanics calculations.
Main Results:
- Peptide 3, with a D,L-alpha-aminoxy acid dimer, adopted a loop conformation with two heterochiral N-O turns.
- This loop segment successfully constrained tetrapeptides 4 and 6 into reverse turn structures stabilized by a 16-membered ring hydrogen bond.
- Steric hindrance prevented reverse turn formation in tetrapeptide 5.
- Computational analysis revealed a novel reverse turn in pentamide 7, featuring two heterochiral N-O turns and multiple hydrogen bonds.
Conclusions:
- D,L-alpha-aminoxy acid dimers can induce specific loop and reverse turn conformations in peptides.
- These findings offer new strategies for designing peptides with defined secondary structures.
- The conformational plasticity of alpha-aminoxy acid-containing peptides is highlighted.
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