Hydrogen and deuterium in myoglobin as seen by a neutron structure determination at 1.5 A resolution.
Ostermann, A., Tanaka, I., Engler, N., Niimura, N., Parak, F.G.(2002) Biophys Chem 95: 183-193
- PubMed: 12062378
- DOI: https://doi.org/10.1016/s0301-4622(01)00255-1
- Primary Citation of Related Structures:
1L2K - PubMed Abstract:
From the first days of protein neutron structure determination sperm whale myoglobin was an object under investigation [Nature 224 (1969) 143, J. Mol. Biol. 220 (1991) 381]. Nevertheless myoglobin is still of interest [Proc. Natl. Acad. Sci. USA 97 (2000) 3872]. The feasibility of the monochromatic neutron diffractometer BIX-3 at the JRR-3M reactor at the JAERI [J. Phys. Chem. Solids 60 (1999) 1623], to collect high-resolution diffraction data in a relatively short time stimulated us to repeat the structural determination of myoglobin. The structure of metmyoglobin has been determined up to a resolution of 1.5 A. The hydrogen atoms were replaced in part, by deuterium soaking the crystals for more than 10 years in D(2)O. A refinement of all atoms has been performed including the refinement of individual mean square displacements and occupancies of the exchangeable protons in backbone hydrogen bonds. A method is described to show clear negative scattering densities of the H atoms. Water molecules within the protein and on the molecule surface are shown. The exchangeability of H atoms is correlated with structural distribution and flexibility.
Organizational Affiliation:
Advanced Science Research Centre, JAERI, Tokai-Mura, Ibaraki 319-1195, Japan.