title: Morphology, size distribution, and aggregate structure of lipopolysaccharide and lipid A dispersions from enterobacterial origin.
abstract: Lipopolysaccharides (LPSs) from Gram-negative bacteria are strong elicitors of the human immune systems. There is strong evidence that aggregates and not monomers of LPS play a decisive role at least in the initial stages of cell activation of immune cells such as mononuclear cells. In previous reports, it was shown that the biologically most active part of enterobacterial LPS, hexa-acyl bisphosphorylated lipid A, adopts a particular supramolecular conformation, a cubic aggregate structure. However, little is known about the size and morphology of these aggregates, regarding the fact that LPS may have strong variations in the length of the saccharide chains (various rough mutant and smooth-form LPS). Thus, in the present paper, several techniques for the determination of details of the aggregate morphology such as freeze-fracture and cryo-electron microscopy, analytical ultracentrifugation, laser backscattering analysis, and small-angle X-ray scattering were applied for various endotoxin (lipid A and different LPS) preparations. The data show a variety of different morphologies not only for different endotoxins but also when comparing different applied techniques. The data are interpreted with respect to the suitability of the single techniques, in particular on the basis of available literature data.
authors.affiliation: Elektronenmikroskopisches Zentrum, Friedrich-Schiller-Universität Jena, Germany.
authors.forename: Walter
authors.initials: W
authors.lastname: Richter
authors.forename: Vitali
authors.initials: V
authors.lastname: Vogel
authors.forename: Jörg
authors.initials: J
authors.lastname: Howe
authors.forename: Frank
authors.initials: F
authors.lastname: Steiniger
authors.forename: Annemarie
authors.initials: A
authors.lastname: Brauser
authors.forename: Michel Hj
authors.initials: MH
authors.lastname: Koch
authors.forename: Manfred
authors.initials: M
authors.lastname: Roessle
authors.forename: Thomas
authors.initials: T
authors.lastname: Gutsmann
authors.forename: Patrick
authors.initials: P
authors.lastname: Garidel
authors.forename: Werner
authors.initials: W
authors.lastname: Mäntele
authors.forename: Klaus
authors.initials: K
authors.lastname: Brandenburg
mesh_terms: D001704:Biopolymers / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002236:Carbohydrate Conformation; D020285:Cryoelectron Microscopy; D054884:Host-Pathogen Interactions / Q000276:immunology; D006801:Humans; D008050:Lipid A / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D009154:Mutation / Q000235:genetics; D012480:Salmonella Infections / Q000276:immunology / Q000382:microbiology*; D019779:Salmonella enterica / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity / Q000648:ultrastructure*; D013329:Structure-Activity Relationship; D014461:Ultracentrifugation; D014961:X-Ray Diffraction
chemical_list: D001704:Biopolymers; D008050:Lipid A