Weakly aligned biological macromolecules in dilute aqueous liquid crystals

A biological macromolecule experiences a small degree of alignment in a dilute aqueous liquid crystal. The alignment is large enough to render reduced dipolar couplings readily observable and yet small enough to preserve qualities of high-resolution solution-state NMR spectra. Residual dipolar couplings are abundant and informative probes about the macromolecular structure, conformational changes and dynamics to explore the molecular mechanism of life, The description of the weak alignment and the interpretation of residual dipolar couplings within the theoretical framework are the prime objectives of this review. (C) 2004 Wiley Periodicals, Inc.