Stimuli-Responsive Peptide Liquid Crystals for Tandem Measurements of Residual Chemical Shift Anisotropy and Residual Dipole Coupling in One Sample.

Abstract

The combined use of residual chemical shift anisotropy (RCSA) and residual dipolar coupling/residual dipole coupling (RDC) could provide highly complementary information about the structure and relative configuration of unknown organic molecules for their elucidation. However, tandem RCSA and RDC measurements in one sample remain a formidable challenge due to their varied testing requirements. Herein, a stimuli-responsive supramolecular liquid crystal self-assembled from an amphiphilic oligopeptide of C₁₉H₃₉-CONH-VVVVKKK-CONH₂ was constructed, which underwent a phasic transformation from anisotropy to isotropy when subjected to a thermal treatment. Both the anisotropic and isotropic phases exhibited good stability, facilitating tandem measurements of ¹³C-{¹H}-RCSA and (¹³C-¹H)-RDC in one sample with no need for special instruments or correction procedures. We expect that the joint use of RCSAs and RDCs will significantly improve data accuracy and utility for structural and configurational determination of small organic molecules and even biomacromolecules.