Halogen-Bearing Peptide Liquid Crystals to Elicit Molecular Alignments for Residual Dipolar Coupling Measurement.

Abstract

Residual dipolar coupling (RDC) not only contributes to the dynamic analysis of proteins but also provides a robust route for the structure determination of small organic compounds. An essential prerequisite for this methodology is the availability of alignment media. Herein, a series of novel peptide-based alignment media are generated by introducing D-type or halogen-bearing amino acids for RDC measurements. Compared with a self-assembled peptide liquid crystal (LC) medium containing _D-amino acid, the incorporation of halogen elements improved the electronegativity of peptide LCs, resulting in enhanced alignment strength toward analytes. Meanwhile, halogen-bearing peptide LCs can provide different orientations relative to non-halogenated peptide media, allowing the acquirement of independent sets of RDCs. The presented peptide LCs not only enrich the existing alignment media but also ignite a way of creating multiple alignment media for independent, non-linearly related sets of RDC measurement.