Identification of the Mycobacterium marinum Apa antigen O-mannosylation sites reveals important glycosylation variability with the M. tuberculosis Apa homologue

► We purified two isoforms of Apa associated to the cell wall of Mycobacterium marinum. ► We established by a combination of lectin blots and MS analysis that this protein is glycosylated. ► We identified by nanoLC-nanoESI-MS/MS sequencing of glycopeptides its major glycosylation sites. ► We established that the glycosylation pattern of Apa from M. marinum was different than M. tuberculosis