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1998 (1)
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1981 (1)
1Author    Helmut Formanek, Hermann WeidnerRequires cookie*
 Title    Three Dimensional Structure of the Carbohydrate Moiety of a Lipopolysaccharide. Computer Calculations  
 Abstract    The cell wall of the mutant R 595 of Salmonella minnesola contains a lipopolysaccharide in which only a trisaccharide consisting of three KDO * residues is linked to a lipid termed lipid A. Considering the sterical requirements o f fourteen rotation angles, we have calculated allowed conformation of this trisyccharide unit and its linkage to lipid A. The calculations have been based on averaged crystallographic data of pyranose rings, ester-, N-acetyl-, phosphate-and carboxylgroups. Because of considerable sterical hindrance, there are unique positions for the rotation around the axes 0 3-C 3 of the glucosamine residue and O j -Q o f KDO residue 1 as well as for the rota­ tion of the N-acetylgroup at the C2-atom of glucosamine. Similarly, the rotation angle o f the carboxylgroup on KDO residue 1 and the rotation angles o f the phosphategroup linked to glucos­ amine are highly restricted, while a large range o f angles is allowed for the bond of the ester group to glucosamine. Chemical sequence analysis yields two possibilities for the linkage between the KDO residues 1 and 2. Linkage of 0 4 o f KDO 1 in equatorial position is restricted to a narrow range of angles, whereas the linkage to 0 4 in axial -and to Oa in axial and equatorial position is unfavourable. Furtheron chemical sequence analysis suggests two ways how to link KDO residue 1 and 3. The linkage to the oxygen atom on C7 o f KDO residue 1 can be described by four, the linkage to the oxygen on C6 with three rotation angles. In either case two of the rotations are highly restricted. In the first case the two remaining angles have large rotational freedom, while the second case is sterically unfavorable. The feasibility of the computer calculations has been demonstrated by the construction of a three-dimensional atomic model. 
  Reference    Z. Naturforsch. 36c, 71—8 (1981); received July 10/November 12 1980 
  Published    1981 
  Keywords    Lipopolysaccharide, Carbohydrate Moiety, Structure 
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 TEI-XML for    default:Reihe_C/36/ZNC-1981-36c-0071.pdf 
 Identifier    ZNC-1981-36c-0071 
 Volume    36 
2Author    Helmut FormanekRequires cookie*
 Title    Possible Orientation of the Fatty Acid Chains in Lipopolysaccharide  
 Abstract    The fatty acid chains of the lipid A component of lipopolysaccharides are hexagonally packed with a lattice periodicity of 4.1 A. The smallest subunit o f this lattice consists of a disaccharide to which seven fatty acid chains are linked representing the hydrophobic part. Carbohydrates and substituted phosphate residues linked to them form the hydrophilic part o f the molecule. Because of sterical reasons and because of the necessity o f a separation of hydrophobic and hydrophilic part, we could derive that the angles o f the hydrocarbon chains with the planes of the two sugar residues should be as vertical as possible and the planes o f both sugar residues should be approximately coplanar forming an angle o f about 180° with one another. Conformation angles for all the theoretically possible linkages o f the disaccaride and of the linkages of the fatty acid residues have been calculated. Between the two-N-acylglucosamine residues theoretically /?-l,4, a -1,6 or /?-l,6 linkages are possible. The experimentally found ß-\,6 linkage has the largest degrees of freedom for its conformation angles. 
  Reference    Z. Naturforsch. 37c, 428 (1982); received March 1 1982 
  Published    1982 
  Keywords    Lipopolysaccharide, Hydrocarbon Chains, Orientation 
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 TEI-XML for    default:Reihe_C/37/ZNC-1982-37c-0428.pdf 
 Identifier    ZNC-1982-37c-0428 
 Volume    37 
3Author    BeateM. EierRequires cookie*
 Title    Superoxide Release in Human Fibroblasts upon Treatment with Culture Supernatants of the Arthritogenic Bacteria Erysipelothrix rhusiopathiae and Mycoplasma arthritidis  
 Abstract    Culture supernatants of the arthritogenic bacteria Mycoplasma pneum onia, M ycoplasm a arthritidis, Borrelia burgdorferi and Erysipelothrix rhusiopathiae stimulated primary cultures of human fibroblasts to release reactive oxygen species into the environment, whereas cell walls and membranes of these bacteria had no effects. Lipopolysaccharides of various gram-negative bacteria and lipid A , the lipid moiety of endotoxines, also failed to stimulate the release of reactive oxygen species by fibroblasts. The stimulatory fractions of the culture supernatants of M ycoplasma arthritidis and E rysip­ elothrix rhusiopathiae exhibited a molecular weight of about 9.5 kDa. After an induction period of 5 min the presence o f the stimulant was not necessary any more. The primary radical released by the fibroblasts was the superoxide anion 0 2'. Radical formation took place continuously over som e hours. Additionally, low-level chemiluminescence of fibroblasts was increased upon stimulation with culture supernatants of M ycoplasm a arthritidis and E ry­ sipelothrix rhusiopathiae. N o irreversible injury o f the fibroblast was caused upon stimulation and the cells exhibited normal proliferation pattern after replacing them to the culture medium. pathiae T28 and Mycoplasma arthritidis I SRI, which serve as a model for rheum atoid arthritis in man (Ajmal, 1970; Cole et al., 1972; Drews, 1972; Schulz, 1980; Schulz et al., 1974; Sikes, 1959). E ry­ sipelothrix rhusiopathiae is a small, gram-positive non mobile coccobacillus causing a chronic arthri­ tis in pigs and rats (Ward, 1922), which has an increasing interest due to its similarities to rheu­ matoid arthritis in man. Beside this pathogenicity it induces natural infections in a wide range of ani­ mals and men (Schulz, 1974; Ajmal, 1969). Mycoplasma arthritidis is the causative agent of arthritis in rats and mice and as Erysipelothrix ar­ thritis represent animal models for rheum atoid ar­ thritis in man (Cole et al., 1971). Mycoplasma are small bacteria lacking a cell wall. Some species posses oligosaccharide chains bound to diglyceride (lipoglycan), which are soluble in organic solvents (Seid et al., 1980). Like the lipopolysaccharides (LPS) of gram negative bacteria they have endo­ toxin-like activities (Razin, 1978). The mem branes of Mycoplasma arthritidis are described to lack these lipoglycans (Razin, 1978). It is unknown whether lipoglycans or cell m em branes of Myco-0939-5075/98/0300-0254 $ 06.00 © 1998 Verlag der Zeitschrift für Naturforschung. All rights reserved. 
  Reference    Z. Naturforsch. 53c, 254 (1998); received D ecem ber 19 1997/February 3 1998 
  Published    1998 
  Keywords    Human Fibroblasts, Superoxide Production, Chemiluminescence, Lipopolysaccharide, Arthritogenic Bacteria 
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 TEI-XML for    default:Reihe_C/53/ZNC-1998-53c-0254.pdf 
 Identifier    ZNC-1998-53c-0254 
 Volume    53