Inositol phosphate capping of the nonreducing termini of lipoarabinomannan from rapidly growing strains of Mycobacterium

摘要: Previous studies have demonstrated that the nonreducing termini of lipoarabinomannan (LAM) from Mycobacterium tuberculosis are extensively capped with mannose residues, whereas those a fast growing sp., once thought to be an attenuated strain M. tuberculosis, not. The noncapped LAM, termed AraLAM, is known more potent than mannose-capped LAM (ManLAM) in inducing functions associated macrophage activation. Using combination chemical and enzymatic approaches coupled atom bombardment-mass spectrometry analysis, we LAMs all strains examined (Erdman, H37Ra, H37Rv), as well bovis BCG strain, extent capping varying between 40 70%. leprae were also found mannoses but at significantly lower level. A novel inositol phosphate motif was identified on minor portion otherwise uncapped arabinan sp. smegmatis ATCC 14468 mc(2)155. In addition, tetra-arabinoside isolated among endoarabinase digestion products AraLAM shown induce tumor necrosis factor-alpha production. Accordingly, concluded characteristic some rapidly spp. It distinct ManLAMs BCG, not only absence mannose-capping containing terminal substituents which may account for its particular potency