FURTHER STRUCTURAL DEFINITION OF A NEW FAMILY OF GLYCOPEPTIDOLIPIDS FROM MYCOBACTERIUM-XENOPI

The highly antigenic surface glycolipids of serovars of the Mycobacterium aviu [GRAPHICS] However, it has recently been shown [Riviere, M., & Puzo, G. (1991) J. Biol. Chem. 266, 9057-9063; Riviere, M., & Puzo, G. (1992) Biochemistry 31, 3575-35801 that the characteristic glycopeptidolipid of a strain of Mycobacterium xenopi is of the structure [GRAPHICS] [monosaccharide, 3-O-CH3-6-deoxy-alpha-L-talopyranose; tetrasaccharide, 2,3,4-tri-O-CH3-alpha-L-rhamnopyranose(1-->3)2-O-lauryl-alpha-L-rhamnopyranose(1-->3)alpha-L-rhamnopyranose(1-3)2,4-di-O-acetyl/lauryl-6-deoxy-alpha-L-glucopyranose]. The type of analyses previously applied to the glycopeptidolipids of M. avium combined with fast atom bombardment mass spectrometry allowed the recognition of other variants of this structure in other strains of M. xenopi: [GRAPHICS] in which the monosaccharide is 2-O-acetyl-3-O-CH3-6-deoxy-alpha-L-talopyranose or 3-O-CH3-6-deoxy-alpha-L-talopyranose, and the disaccharide is 4-O-octanoyl(or decanoyl)-alpha-L-rhamnopyranose(1-->3)2-O-lauryl-alpha-L-rhamnopyranose or alpha-L-rhamnopyranose(1-->3)2-O-lauryl-alpha-L-rhamnopyranose. Recognition of serine-containing glycopeptidolipids substituted in one case with a tetrasaccharide and in another case with a disaccharide unit implies that M. xenopi, an important opportunistic pathogen, exists as a serocomplex in nature.