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Identification of the Mycobacterium marinum Apa antigen O-mannosylation sites reveals important glycosylation variability with the M. tuberculosis Apa homologue
- Source :
- Journal of Proteomics. 75:5695-5705
- Publication Year :
- 2012
- Publisher :
- Elsevier BV, 2012.
-
Abstract
- The 45/47 kDa Apa, an immuno-dominant antigen secreted by Mycobacterium tuberculosis is O-mannosylated at multiple sites. Glycosylation of Apa plays a key role in colonization and invasion of the host cells by M. tuberculosis through interactions of Apa with the host immune system C-type lectins. Mycobacterium marinum (M.ma) a fish pathogen, phylogenetically close to M. tuberculosis, induces a granulomatous response with features similar to those described for M. tuberculosis in human. Although M.ma possesses an Apa homologue, its glycosylation status is unknown, and whether this represents a crucial element in the pathophysiology induced by M.ma remains to be addressed. To this aim, we have identified two concanavalin A-reactive 45/47 kDa proteins from M.ma, which have been further purified by a two-step anion exchange chromatography process. Advanced liquid chromatography-nanoESI mass spectrometry-based proteomic analyses of peptides, derived from either tryptic digestion alone or in combination with the Asp-N endoproteinase, established that M.ma Apa possesses up to seven distinct O-mannosylated sites with mainly single mannose substitutions, which can be further extended at the Ser/Thr/Pro rich region near the N-terminus. This opens the way to further studies focussing on the involvement and biological functions of Apa O-mannosylation using the M.ma/zebrafish model.
- Subjects :
- Antigens, Bacterial
Glycosylation
biology
Biophysics
Mannose
Mycobacterium tuberculosis
biology.organism_classification
Biochemistry
Microbiology
chemistry.chemical_compound
Bacterial Proteins
chemistry
Antigen
Concanavalin A
Mycobacterium marinum
biology.protein
Amino Acid Sequence
Pathogen
Peptide sequence
Glycoproteins
Subjects
Details
- ISSN :
- 18743919
- Volume :
- 75
- Database :
- OpenAIRE
- Journal :
- Journal of Proteomics
- Accession number :
- edsair.doi.dedup.....4e461d2d18798d119e7ec3dc32c51b5d