Structure and molecular dynamics are probed in liquid crystalline and solid phases via deuterium NMR spectroscopy, and associated molecular modeling. Specifically labeled helical synthetic polypeptides are the primary target of the proposed research; a quantitative description of sidechain secondary structure/dynamics across the entire concentration range will result. Tests of current models of the isotropic-nematic phase transition are planned; a direct NMR measurement of the critical order parameter at the transition is proposed. The dynamical averaging of flexible solutes in nematic solvents is also proposed in this research; a quantitative estimate of the constraints imposed on alkyl chains of solutes by the nematic mean field will result. This in turn will enable detailed characterization of alkyl chains in a variety of uniaxial environments, in particular, in bilayers of model membranes. Each of the proposed systems are designed to increase our understanding of molecular dynamics in a state of aggregation that more closely resemble a subcellular environment - the liquid crystal state.
| Samulski, E T (1985) Macromolecular structure and liquid crystallinity. Faraday Discuss Chem Soc :7-20 |
