Alignment of biological macromolecules in novel nonionic liquid crystalline media for NMR experiments

n-Alkyl-poly(ethylene glycol)/n-alkyl alcohol and glucopone/n-hexanol mixtures are shown to form dilute liquid crystalline phases in aqueous solution which are suitable for partial alignment of biological macromolecules in a magnetic field. The constituent compounds are commercially available and inexpensive. The poly(ethylene glycol)-based systems are uncharged and thus insensitive with respect to pH, little sensitive with respect to salt, and tolerant against high protein concentrations. They are demonstrated to be suitable for measurements of residual dipolar couplings in proteins, DNA, and a protein/DNA complex. The stability range of the lamellar phase with respect to temperature was explored for different mixtures and guidelines are provided for the use of these lyotropic systems in NMR spectroscopy.