Lipopolysaccharides of Salmonella minnesota rough mutants were treated with 20 mM acetate buffer pH 4.4 at 70 degrees C/3 h. After dialysis of the hydrolysates about one third of the total 3-deoxy-D-mannooctulosonic acid (dOclA) content but no neutral sugars were found in the dialysate. By high-voltage paper electrophoresis, a compound with the mobility of 1.2 relative to dOclA could be isolated from the dialysate. It was identified as a dOclA disaccharide by hydrolysis without or after reduction with sodium borohydride and by analysis with the thiobarbituric acid assay under different conditions. The ketosidic linkage in the disaccharide is assumed to be 2.4 or 2.5.
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http://dx.doi.org/10.1111/j.1432-1033.1983.tb07250.x | DOI Listing |
J Biol Chem
September 2002
Department of Biochemistry, Duke University Medical Center, Durham, North Carolina 27710, USA.
Escherichia coli MsbA, the proposed inner membrane lipid flippase, is an essential ATP-binding cassette transporter protein with homology to mammalian multidrug resistance proteins. Depletion or loss of function of MsbA results in the accumulation of lipopolysaccharide and phospholipids in the inner membrane of E. coli.
View Article and Find Full Text PDFCan J Microbiol
March 1996
Department of Biology, University of Waterloo, ON, Canada.
An extracellular surface-active agent, PM-factor, was obtained by high-speed centrifugation from the culture broth of Pseudomonas marginalis PD-14B. PM-factor exhibited emulsifying activity on a broad spectrum of hydrocarbon liquids, including aromatics, aliphatics, crude oil, and creosote. The factor appeared as ball-shaped particles of varying diameter when examined by electron microscopy (0.
View Article and Find Full Text PDFAntimicrob Agents Chemother
October 1991
Département de Microbiologie Médicale, Centre Médical Universitaire, Geneva, Switzerland.
Routes of quinolone permeation in Pseudomonas aeruginosa were investigated by using sparfloxacin as a prototype compound. [14C]sparfloxacin cell labeling was 13 to 28% lower in three protein D2-deficient mutants resistant to imipenem than in their imipenem-susceptible counterparts. In four impermeability-type quinolone-resistant strains isolated from pefloxacin-treated animals, we observed two- to fourfold-greater resistance to imipenem, reduced protein D2 expression in the outer membrane according to Western blotting (immunoblotting), and 25 to 29% decreased cell labeling with imipenem.
View Article and Find Full Text PDFEur J Biochem
May 1991
Institut für Kristallographie, Freien Universität Berlin, Federal Republic of Germany.
Molecular modelling techniques have been applied to compute the conformation accessible to bacterial deep rough lipopolysaccharide of Escherichia coli (Re-LPS). Analyses of the results showed that the models typically exhibit a tilt of the diglucosamine backbone with respect to the membrane normal of 53 +/- 7 degrees while both the glucosamine ring planes are oriented approximately parallel to the membrane normal. Different models were found to show compact and elongated types of acyl chain arrangements, both producing anisotropic lateral dimensions of the models of 1.
View Article and Find Full Text PDFAntimicrob Agents Chemother
March 1991
Département de Microbiologie Médicale, Centre Médical Universitaire, Geneva, Switzerland.
Mechanisms of resistance to pefloxacin were investigated in four isogenic Pseudomonas aeruginosa strains: S (parent isolate; MIC, 2 micrograms/ml), PT1 and PT2 (posttherapy isolates obtained in animals; MICs, 32 and 128 micrograms/ml, respectively), and PT2-r (posttherapy isolate obtained after six in vitro subpassages of PT2; MIC, 32 micrograms/ml). [2-3H]adenine incorporation (indirect evidence of DNA gyrase activity) in EDTA-permeabilized cells was less affected by pefloxacin in PT2 and PT2-r (50% inhibitory concentration, 0.27 and 0.
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