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Updated: Oct 7, 2026

15N CPMG Relaxation Dispersion for the Investigation of Protein Conformational Dynamics on the µs-ms Timescale
Published on: April 19, 2021
Conformational study on poly [gamma-(alpha-phenethyl)-L-glutamate] using vibrational circular dichroism spectroscopy
1Division of Molecular Biophysics, Institute for Protein Research, Osaka University, Yamadaoka 3-2, Suita, Osaka 565-0871, Japan.
Abstract:
Vibrational circular dichroism (VCD) and IR absorption spectra are obtained in a chloroform solution for poly[gamma-((R)-alpha-phenethyl)-L-glutamate] (PRPLG) and poly[gamma-((S)-alpha-phenethyl)-L-glutamate] (PSPLG), whose only structural difference is an opposite chiral center in the side chain. Their characteristic amide A, I, and II bands show VCD patterns quite similar to those of poly[gamma-benzyl-L-glutamate] (PBLG), indicating that the secondary structure of these polypeptides is a right-handed alpha-helix. The VCD spectra in the CH stretching region exhibit different patterns for PRPLG and PSPLG, reflecting the chirality difference in the side chains. This difference is interpreted on the basis of the additivity of optical activity contributions from the main chain conformation and the chirality difference in the side chains. The results indicate that a VCD difference spectrum of the CH stretching region is a useful diagnostic tool for elucidating local chirality differences.
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