PolysacDB Lipooligosaccharide 1620
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[edit] Carbohydrate Name
Lipooligosaccharide
[edit] Carbohydrate Class
Lipopolysaccharide
[edit] Source Microbe
Moraxella catarrhalis B strain 26397
[edit] Basic Structure
LOS consists of an oligosaccharide and lipid A and is similar to the lipopolysaccharide (LPS) of gramnegative enteric pathogens, but it lacks the O-antigenic side chain of repeating units characteristic of classical LPS. The oligosaccharide part consists of the following residues : α-D-Galp-(1-->4)-β-D-Galp-(1-->4)-α-D-Glcp-(1-->2)-β-D-Glcp-(1-->4)-α-D-Glcp [branched to α-D-Galp-(1-->4)-&blpha;-D-Galp-(1-->4)-α-D-Glcp-(1-->2)-β-D-Glcp-(1-->6)] and [branched to β-D-Glcp-(1-->3)] -(1-->5)-Kdo
[edit] Proposed functions
Moracella lipooligosaccharide is a potential virulence factor
[edit] Antigenic Nature used to produce antibodies
Glycoconjugates
[edit] Carrier Name
Tetanus toxoid
[edit] Conjugation Method
Adipic acid dihydrazide [ADH] was introduced to the carboxyl group of Kdo moiety of the detoxified lipooligosaccharide [LOS] to form adipic hydrazide (AH)-dLOS derivatives, using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide HCl (EDC) and N-hydroxysulfosuccinimid. dLOS (96 mg) was dissolved in 12 ml of 287 mM ADH (50 mg/ml, molar ratio of ADH to dLOS is 108 to 1 based on an estimated Mrof 3,000 for dLOS). AH-dLOS (45 mg) was dissolved with 4.5 ml of 0.2 M NaCl to make a 10 mg/ml solution of AH-dLOS. For the conjugation reaction, each 20 mg of AH-dLOS solution (2 ml in volume) was mixed with 10 mg of cross-reactive mutant (CRM) of diphtheria toxin (0.44 ml in volume). The initial concentration of AH-dLOS or CRM was 8.20 or 4.10 mg/ml. The molar ratio of AH-dLOS to CRM (Mr 67,000) was 45 to 1. The pH was adjusted to 5.0-5.2 with 0.1 M HCl, followed by addition of 0.05 M EDC. The reaction was maintained at pH 5.0 to 5.2 for 4 h at 4C, then adjusted to pH 7.0, dialyzed against 0.9% NaCl for 2 to 3 days, centrifuged, and passed through a Sephacryl S-300 column (2.6 by 90 cm) in 0.9% NaCl. Peaks that contained both protein and carbohydrate were pooled and designated as dLOS-TT or dLOS-CRM. Both conjugates were analyzed for their composition of carbohydrate and protein using dLOS and bovine serum albumin (BSA) as standards
[edit] Antibodies
Polysera
[edit] Antibody type and class
N/A
[edit] Assay System
ELISA, Bactericidal assay and immunoblotting
[edit] Cross-reactivity
This antisera was specific to Serotype B and reacted with nine of twelve clinical isolates studied
[edit] Proposed epitopes
N/A
[edit] Proposed Utility
This antisera showed elevated complement-mediated bactericidal activity against the homologous strain
