Crystallization of R-form lipopolysaccharides from Salmonella minnesota and Escherichia coli.
AUTOR(ES)
Kato, N
RESUMO
Salmonella minnesota Re and Ra lipopolysaccharides (LPSs) and Escherichia coli K-12 LPS formed three-dimensional crystals, either hexagonal plates (preferential growth along the a axis) or solid columns (preferential growth along the c axis), when they were 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 degrees C for 10 days. Analyses of crystals suggested that they consist of hexagonal lattices with the a axis (a side of the lozenge as a unit cell on the basal plane) of 0.462 nm for all these three kinds of LPSs and the c axes (perpendicular to the basal plane) of 5.85, 8.47, and 8.75 nm for S. minnesota Re and Ra LPSs and E. coli K-12 LPS, respectively, and that hydrocarbon chains of the lipid A portion play the leading part in crystallization, whereas the hydrophilic part of the lipid A (the disaccharide backbone) and R core exhibit a disordered structure or are in a random orientation. The phenomenon of doubling of the a axis to 0.924 nm was observed with crystals of S. minnesota Re LPS when they were incubated in 70% ethanol for an additional 180 days, but not with crystals of S. minnesota Ra LPS or E. coli K-12 LPS. S. minnesota S-form LPS possessing the O-antigen-specific polysaccharide and S. minnesota free lipid A obtained by acid hydrolysis of Re LPS did not crystallize under the same experimental conditions.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=208628Documentos Relacionados
- High-molecular-weight components in lipopolysaccharides of Salmonella typhimurium, Salmonella minnesota, and Escherichia coli.
- Common lipopolysaccharide specificity: new type of antigen residing in the inner core region of S- and R-form lipopolysaccharides from different families of gram-negative bacteria.
- Formation of a hexagonal lattice structure by an R-form lipopolysaccharide of Klebsiella sp.
- Detection of antibodies against lipopolysaccharides of Escherichia coli and Salmonella R and S strains by immunoblotting.
- Repression of alkaline phosphatase in Salmonella typhimurium carrying a phoA+ phoR- episome from Escherichia coli.