NMR Investigation of Deuterated Collagen

Abstract

KNOWLEDGE of the structures of biological macromolecules stems almost exclusively from X-ray diffraction studies. In conjunction with molecular models, the diffraction patterns may be used to assign the positions of atoms other than hydrogen, and ultimately their relative angular spacing. We may describe the information as translatioiial in character and this can only be interpreted in rotational, or angular, terms with the help of model building. Further, the assignment of any hydrogen bonds is not possible. We demonstrate here that the orientation of peptide groups may be determined relative to a fibre axis directly from nuclear magnetic resonance (NMR) measurements of the quadrupole couplings experienced by deuterium nuclei substituted for the peptide hydrogens. The couplings observed are sensitive to the type of hydrogen bond present and may become diagnostic for them.