Crystallization of lipopolysaccharide from a Salmonella typhimurium semi-rough (SR) mutant.
Salmonella typhimurium SR-form lipopolysaccharide (LPS), consisting of a single repeating unit of the O-antigenic polysaccharide, linked to the R-core consisting of oligosaccharide that is, in turn, linked to lipid A, formed crystals whose shapes were hexagonal plates, discoids, and solid columns when precipitated by the addition of 2 volumes of 95% ethanol containing 375 mM MgCl2 and kept in 70% ethanol containing 250 mm MgCl2 at 4 C for 10 days. Among these crystals, the basic form is considered to be the hexagonal plates. Analyses of hexagonal plate crystals showed that they consist of hexagonal lattices with a lattice constant (a axis) of 4.62 A and longitudinal axis (c axis) of approximately 100 A. In X-ray diffraction patterns in the low-angle region, crystals of S. typhimurium SR-form LPS exhibited much less distinct reflections when compared with crystals of synthetic Escherichia coli-type lipid A. In contrast to the previous finding that S. minnesota S-form LPS possessing the O-antigenic polysaccharide does not crystallize under the same experimental conditions as used in the present study, the presence of a single repeating unit of the O-antigenic polysaccharide does not inhibit crystallization.
Ito
H
H
Nagoya University School of Health Sciences, Aichi, Japan.
Naito
S
S
Arakawa
Y
Y
Sasaki
K
K
Kato
N
N
D002236:Carbohydrate Conformation; D018360:Crystallography, X-Ray; D006801:Humans; D008070:Lipopolysaccharides / Q000737:chemistry*; D009154:Mutation; D012486:Salmonella typhimurium / Q000737:chemistry* / Q000235:genetics / Q000648:ultrastructure
D008070:Lipopolysaccharides