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A novel peptide conformation: the γ-bend ribbon
Bruno Drouillat1, Cristina Peggion, Barbara Biondi
1Institut Lavoisier de Versailles, UMR CNRS 8180, University of Versailles St-Quentin en Yvelines, 78035 Versailles, France. karen.wright@uvsq.fr.
Organic & Biomolecular Chemistry
|October 16, 2018
Summary
This study characterizes the gamma-bend ribbon conformation, previously unstudied, using various spectroscopic methods. Researchers confirmed the existence of the gamma-helix in peptides, advancing our understanding of peptide structure.
Area of Science:
- * Structural biology and peptide chemistry.
- * Investigating novel peptide conformations and their structural underpinnings.
Background:
- * The relationship between peptide ribbon conformations and helical structures is well-established for beta-bends and 310-helices.
- * The structural characterization of the gamma-bend ribbon and its corresponding gamma-helix has remained largely unexplored due to a lack of experimental data.
Purpose of the Study:
- * To provide the first experimental characterization of the gamma-bend ribbon conformation.
- * To investigate the formation of the gamma-helix in synthetic peptide oligomers.
- * To elucidate the structural properties of gamma-bends in both crystal and solution states.
Main Methods:
- * X-ray diffraction for crystal structure analysis.
- * Fourier-transform infrared (FT-IR) absorption spectroscopy.
- * Electronic circular dichroism (CD) spectroscopy.
- * 2D Nuclear Magnetic Resonance (2D-NMR) spectroscopy.
- * Synthesis of homo-chiral sequential dipeptide oligomers incorporating (S)-Alanine and a gamma-bend inducer, (S)-Cα-methyl-azetidine-carboxylic acid.
Main Results:
- * Experimental evidence confirming the existence and stability of the gamma-bend ribbon conformation.
- * Characterization of the 3D structures of gamma-bend ribbons in both solid-state and solution.
- * Validation of the gamma-helix as a recurring structural motif in specific peptide sequences.
Conclusions:
- * The study successfully characterized the gamma-bend ribbon conformation, filling a significant gap in peptide structural knowledge.
- * The findings provide the first experimental authentication of the gamma-helix, establishing its presence in synthetic peptides.
- * This work lays the foundation for further research into the role and prevalence of gamma-helices in biological systems and peptide design.
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