title: Identification, isolation, and structural studies of the outer membrane lipopolysaccharide of Caulobacter crescentus.
abstract: The lipopolysaccharide (LPS) of the outer membrane of Caulobacter crescentus was purified and analyzed. Two distinct strains of the species, NA 1000 and CB2A, were examined; despite differences in other membrane-related polysaccharides, the two gave similar LPS composition profiles. The LPS was the equivalent of the rough LPS described for other bacteria in that it lacked the ladder of polysaccharide-containing species that results from addition of variable amounts of a repeated sequence of sugars, as detected by gel electrophoresis in smooth LPS strains. The purified LPS contained two definable regions: (i) an oligosaccharide region, consisting of an inner core of three residues of 2-keto-3-deoxyoctonate, two residues of alpha-L-glycero-D-mannoheptose, and one alpha-D-glycero-D-mannoheptose unit and an outer core region containing one residue each of alpha-D-mannose, alpha-D-galactose, and alpha-D-glucose, with the glucose likely phosphorylated and (ii) a region equivalent to the lipid A region of the archetype, consisting primarily of an esterified fatty acid, 3-OH-dodecanoate. The lipid A-like region was resistant to conclusive analysis; in particular, although a variety of analytical methods were used, no amino sugars were detected, as is found in the lipid A of the LPS of most bacteria.
authors.affiliation: Department of Microbiology, University of British Columbia, Vancouver, Canada.
authors.forename: N
authors.initials: N
authors.lastname: Ravenscroft
authors.forename: S G
authors.initials: SG
authors.lastname: Walker
authors.forename: G G
authors.initials: GG
authors.lastname: Dutton
authors.forename: J
authors.initials: J
authors.lastname: Smit
mesh_terms: D000942:Antigens, Bacterial / Q000737:chemistry*; D016935:Caulobacter crescentus / Q000737:chemistry*; D002462:Cell Membrane / Q000737:chemistry; D005690:Galactose / Q000032:analysis; D014644:Genetic Variation; D005947:Glucose / Q000032:analysis; D006539:Heptoses / Q000032:analysis; D007850:Lauric Acids / Q000032:analysis; D008050:Lipid A / Q000032:analysis; D008055:Lipids / Q000032:analysis; D008070:Lipopolysaccharides / Q000737:chemistry* / Q000302:isolation & purification*; D008358:Mannose / Q000032:analysis; D009844:Oligosaccharides / Q000737:chemistry; D013400:Sugar Acids / Q000032:analysis
chemical_list: D000942:Antigens, Bacterial; D006539:Heptoses; D007850:Lauric Acids; D008050:Lipid A; D008055:Lipids; D008070:Lipopolysaccharides; D009844:Oligosaccharides; D013400:Sugar Acids; C023023:lipid-linked oligosaccharides; C002532:2-keto-3-deoxyoctonate; C022145:3-hydroxydodecanoic acid; D005947:Glucose; D008358:Mannose; D005690:Galactose