Calcium interactions with D-glucans: crystal structure of alpha, alpha-trehalose-calcium bromide monohydrate |
| |
Authors: | W J Cook C E Bugg |
| |
Institution: | Institute of Dental Research and Department of Biochemistry, University of Alabama in Birmingham, University Station, Birmingham, Alabama 35294 U. S. A. |
| |
Abstract: | Three-dimensional X-ray diffraction data were used to determine the crystal structure of α,α-trehalose-calcium bromide monohydrate, a model system for investigation of factors involved in the binding of calcium ions to d-glucans of dental plaques. Crystals of C12H22O11 ·CaBr2·H2O are orthorhombic, space group C2221, with a 11.058(1) b 11.537(1), c 15.101(1) Å, and Z 4. Intensity data for 925 independent reflections were measured with an automated diffractometer. A trial structure, obtained by the heavy-atom method, was refined by least-squares to R 0.03. An outstanding feature of the crystal packing is the interaction of trehalose molecules with calcium ions. Each calcium is coordinated to hydroxyl groups from four symmetry-related d-glucose moieties, thereby cross-linking the trehalose molecules. Similar interactions between calcium ions and the d-glucose residues of extracellular d-glucans may be of importance in the agglutination processes involved in dental-plaque formation. |
| |
Keywords: | |
本文献已被 ScienceDirect 等数据库收录! |
|