title: Crystallization of synthetic Escherichia coli-type lipid A.
abstract: Synthetic Escherichia coli-type lipid A formed hexagonal plate crystals when it was precipitated by the addition of 2 volumes of 95% ethanol containing 375 mM MgCl2 and incubated in 70% ethanol containing 250 mM MgCl2 at 4 C for 10 days. Analyses of crystals by electron diffraction and synchrotron X-ray diffraction showed that crystals consist of hexagonal lattices with the lattice constant (a side of the lozenge as a unit cell on the basal plane) of 4.62 angstrom and the longitudinal axis (perpendicular to the basal plane) of 49.3 +/- 1.3 angstrom. Results suggest that the previous finding that various kinds of R-form lipopolysaccharides crystallized but free lipid A isolated by acid hydrolysis from Re lipopolysaccharide did not crystallize under the same experimental conditions (Kato et al, J. Bacteriol., 172:1516-1528, 1990) is due to structural changes of lipid A occurring during the procedure of isolation of free lipid A.
authors.affiliation: Department of Bacteriology, Nagoya University School of Medicine, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Kato
authors.forename: S
authors.initials: S
authors.lastname: Naito
authors.forename: Y
authors.initials: Y
authors.lastname: Arakawa
authors.forename: T
authors.initials: T
authors.lastname: Sugiyama
authors.forename: H
authors.initials: H
authors.lastname: Ito
authors.forename: M
authors.initials: M
authors.lastname: Ohta
authors.forename: K
authors.initials: K
authors.lastname: Sasaki
mesh_terms: D003460:Crystallization; D018360:Crystallography, X-Ray; D004926:Escherichia coli / Q000737:chemistry*; D008050:Lipid A / Q000737:chemistry*; D008854:Microscopy, Electron
chemical_list: D008050:Lipid A