| PolysacDB ID | 1030 |
| Carbohydrate Name | O-deacetylated Glucurunoxylomannan (Drugpedia) |
| Carbohydrate Class | Capsular polysaccharide |
| Microbe | Cryptococcus neoformans Serotype C (NCBI Taxonomy) (Drugpedia) |
| Basic Structure | The GXM is a high-molecular-weight linear (1-->3)-α-D-mannan substituted with single (1-->2)-β-xylosyl and (1-->2)-β-glucuronosyl residues. 0 acetylation occurs on the C-6 of about half of the mannose residues. The molar ratio of xylose-mannose-glucuronic acid is 2:3:1 for serotype A
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| BCSDB Structure | 73 |
| Proposed functions | The capsular glucuronoxylomannan (GXM) of C. neoformans is anantiphagocytic and tolerogenic polysaccharide and potentiates virulence |
| Antigenic Nature used to produce antibodies | Glycoconjugates |
| Carrier Name | Bovine serum albumin |
| Conjugation Method | GXM of C. neoformans serotype A 9759 was activated with 2,2,2-trifluoroethanesulfonyl chloride (tresyl chloride) and was coupled to BSA-AH. GXM (100 mg) was suspended in acetone, and 75 ul of pyridine was added. Tresyl chloride (50 ,ul) was added and stirred for 10 min. The activated GXM was washed with ethanol containing 5 mM HCI, washed with absolute ethanol, and dried in vacuo. Activated GXM (46 mg) was dissolved in 1.5 ml of 0.2 M NaH2PO4 buffer (pH 7.5) (coupling buffer), and BSA-AH was added (25 mg in 0.5 ml of the same buffer). The reaction was stirred overnight at 24°C. The precipitate was removed by centrifugation, and the supernatant was applied to a column (90 by 2.5 cm) of Sepharose CL-6B equilibrated with 0.05 M Tris hydrochloride-0.1 M NaCl buffer (pH 7.6). The flow rate was 35 ml/h. Fractions containing carbohydrate and protein appeared in the void volume. They were pooled, dialyzed, and lyophilized (yield, 33 mg). The conjugate was then rechromatographed (yield, 17 mg) |
| Antibodies | Mab CD6 |
| Antibody type and class | IgG1 |
| Assay System | Indirect immunofluorescence |
| Cross-reactivity | This antibody cross-reacted with all 4 serotypes- A, B, C and D. |
| Proposed epitopes | Glucuronic acid was proposed to be the important constituent of the epitope. However the epitope also probably contained xylose and was influencedto a minor extent by the presence of O-acetyl groups |
| IEDB Epitope | N/A |
| Proposed Utility | The ability to produce a MAb against an epitope shared by many serotypes may have value for the detection of cryptococcal antigens in body fluids. This antibody also has potent opsonic activity |
| Curator ID | AA + AS |
| Date of Curation | 09-01-2010
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| References | PMC259921 |