PolysacDB: A comprehensive database of microbial polysaccharide antigens and their antibodies

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Citation: Aithal A, Sharma A, Joshi S, Raghava GPS, Varshney GC (2012) PolysacDB: A Database of Microbial Polysaccharide Antigens and Their Antibodies. PLoS ONE 7(4): e34613. doi:10.1371/journal.pone.0034613
Total Entries - 3

Entry No. - 1   [TOP]
PolysacDB ID2602
Carbohydrate NameCapsular polysaccharide   (Drugpedia)
Carbohydrate ClassCapsular polysaccharide
MicrobeCryptococcus neoformans Serotype D   (NCBI Taxonomy)   (Drugpedia)
Basic StructureThe capsular polysaccharide has a linear α-(1-->3)-linked mannose backbone that is substituted with nonreducing D-xylosyl and D-glucuronosyl acid groups. The mannose backbone is partially O-acetylated
BCSDB Structure136943
Proposed functionsThe capsular polysaccharide is an important virulence factor
Antigenic Nature used to produce antibodiesGlycoconjugates
Carrier NameSheep erythrocytes
Conjugation MethodThe capsular polysaccharide was adsorbed with 0.1 ml of packed sheep erythrocytes for 2 hours at room temperature
AntibodiesMab 386
Antibody type and classN/A
Assay SystemELISA and Immunodiffusion
Cross-reactivityThis antibody has a highly variable cross-reactivity. It cross reacts with most strains of Serotype A and D. It cross reacts with only one strain of serotype B and 2 strains of serotype C. does not show a reaction with ELISA
Proposed epitopesSince Mab 386 does not show any positive results with ELISA, it is suggested that binding of polysaccharides to plates coated with poly-L-lysine altered the carboxyl residues that may form part of an epitope recognized by the antibody
IEDB EpitopeN/A
Proposed UtilityUsed to differentiate various strains of all serotypes
Curator IDAA + AS
Date of Curation15-07-2011
References2476401


Entry No. - 2   [TOP]
PolysacDB ID2605
Carbohydrate NameCapsular polysaccharide   (Drugpedia)
Carbohydrate ClassCapsular polysaccharide
MicrobeCryptococcus neoformans Serotype D   (NCBI Taxonomy)   (Drugpedia)
Basic StructureThe capsular polysaccharide has a linear α-(1-->3)-linked mannose backbone that is substituted with nonreducing D-xylosyl and D-glucuronosyl acid groups. The mannose backbone is partially O-acetylated
BCSDB Structure136943
Proposed functionsThe capsular polysaccharide is an important virulence factor
Antigenic Nature used to produce antibodiesGlycoconjugates
Carrier NameKeyhole limpet hemocyanin
Conjugation MethodForty milligrams of crude polysaccharide was dissolved in 4 ml of physiological saline solution (PSS). One milliliter of 1% cyanuric chloride in dimethylformamide was added to the polysaccharide solution and stirred for 1 h at 48°C. KLH in PSS (100 mg/2ml) was added and stirred for 1 h at 258°C, and the solution was then incubated at 48C for 18 h. The solution was dialyzed against water for 30 h and centrifuged. The protein concentration in the supernatant was adjusted to 2 mg/ml, 1/9 volume of 10% aluminum potassium sulfate solution was added, and the pH was adjusted to 6.5 with 10% sodium carbonate. The precipitated antigen was removed by centrifugation and resuspended in PSS
AntibodiesMab CRND8
Antibody type and classIgM
Assay SystemELISA and CSA[Cell Slide Agglutination]
Cross-reactivityThis antibody cross-reacted with Serotype A and D serotypes
Proposed epitopesO-acetylated glucurunoxylomannan
IEDB EpitopeN/A
Proposed UtilityUsed to differentiate various strains of all serotypes
Curator IDAA + AS
Date of Curation16-07-2011
ReferencesPMC170253


Entry No. - 3   [TOP]
PolysacDB ID2642
Carbohydrate NameCapsular polysaccharide   (Drugpedia)
Carbohydrate ClassCapsular polysaccharide
MicrobeCryptococcus neoformans Serotype D   (NCBI Taxonomy)   (Drugpedia)
Basic StructureThis polysaccharide is a high m.w. polymer with a linear α-(1-->3)-linked mannose backbone that is substituted with non-reducing D-xyIosyal and D-glucosyluronic acid groups. O-Acetylation varies with the serotype. Type D is the most heavily O-acetylated
BCSDB Structure136943
Proposed functionsAntiphagocytic ; an important virulence factor
Antigenic Nature used to produce antibodiesGlycoconjugates
Carrier NameMethylated bovine serum albumin
Conjugation MethodA saline solution containing 500 pg of cryptococcal polysaccharide was mixed with 500 pg aqueous methylated bovine serum albumin. The volume was brought to 2 ml with sterile distilled water
AntibodiesPolysera
Antibody type and classIgG
Assay SystemAntiserum to untreated cryptococcal polysaccharide was enriched for O-acetyl and carboxyl specific antibody respectively. The antisera was then used in ouchterlony double diffusion.
Cross-reactivityN/A
Proposed epitopesN/A
IEDB EpitopeN/A
Proposed UtilityO-acetyl and carboxyl groups are strong and distinct physicochemical determinants on cryptococcal polysaccharide. The enriched antiserum displayed a level of opsonic activity that was similar to non-enriched antiserum. This showed that neither O-acetyl nor carboxyl groups were responsible for inhibition of phagocytosis by cryptococcal polysaccharide
Curator IDAA + AS
Date of Curation30-07-2011
References15271943


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