Related Experiment Video
Updated: Jun 19, 2026

High-Pressure NMR Experiments for Detecting Protein Low-Lying Conformational States
Published on: June 29, 2021
Effect of pressure on the secondary structure of coiled coil peptide GCN4-p1
Hiroshi Imamura1, Yasuhiro Isogai, Takahiro Takekiyo
1Graduate School of Science and Engineering, Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan.
Abstract:
It has recently been demonstrated that pressure induces folding of the alpha-helix of an alanine-based peptide (AK20), which is a monomer in water (Imamura and Kato, Proteins 2009;76:911-918). The present study focused on a coiled coil peptide GCN4-p1, the alpha-helices of which associate via a hydrophobic core, to examine whether the pressure stability of the alpha-helices depends on the hydrophobic core. Fourier transform infrared spectroscopy was used to investigate the effect of pressure on the secondary structures of GCN4-p1. The infrared spectra of GCN4-p1 shows the two amide I' peaks at approximately 1650 and approximately 1630 cm(-1) stemming from the solvent-inaccessible alpha-helix and the solvent-accessible alpha-helix, respectively. The intensities of both the peaks increase with increasing pressure, whereas they decrease with increasing temperature. This indicates that pressure induces both the alpha-helices of GCN4-p1 to fold. The present result suggests that the positive volume change upon unfolding of an alpha-helix is a common characteristic of peptides. The pressure-induced stabilization of the alpha-helices is discussed in comparison with the pressure denaturation of proteins.
More Related Videos
10:31Residue-Specific Exchange of Proline by Proline Analogs in Fluorescent Proteins: How "Molecular Surgery" of the Backbone Affects Folding and Stability
Published on: February 3, 2022
11:19Site Directed Spin Labeling and EPR Spectroscopic Studies of Pentameric Ligand-Gated Ion Channels
Published on: July 4, 2016
Related Concept Videos
Protein Folding
Protein Folding
Protein Structure Is Critical to Its Biological Function
Proteins perform a wide range of biological functions such as catalyzing chemical reactions, providing...
Protein Folding
Protein Organization
Protein Organization
The primary structure of a protein is its amino acid sequence.
Protein and Protein Structure
A protein's shape is critical to its function. For example, an enzyme can...