Oligosaccharides accumulated in the bovine beta-mannosidosis kidney

The phenotype of bovine beta-mannosidosis (beta-mannosidase deficiency), recently identified in Salers cattle, is similar to the caprine form of the disease (Abbitt et al., 1991). This investigation was designed to characterize accumulated kidney oligosaccharides in bovine beta-mannosidosis. Oligosaccharides were extracted from the kidney of an affected Salers calf and purified by chromatographic techniques. The amount of accumulating oligosaccharides in 1 g of wet tissue was about 21 mumol. Structures of derivatized oligosaccharides were characterized by high-performance liquid chromatography, mass spectrometry, methylation analysis and sequential exoglycosidase digestions. The major accumulating oligosaccharides were Man beta 1-4GlcNAc and Man beta 1-4GlcNAc beta 1-4GlcNAc. Oligosaccharides accumulating in minor amounts were Man beta 1-4GlcNAc beta 1-4Man beta 1-4GlcNAc, Man alpha 1-6Man beta 1-4GlcNAc beta 1-4GlcNAc and Man beta 1-4GlcNAc beta 1-4Man beta 1-4GlcNAc beta 1-4GlcNAc. As in caprine beta-mannosidosis, oligosaccharides with terminal beta-mannose residues and cleaved as well as uncleaved chitobiose linkages were identified in bovine beta-mannosidosis kidney. The accumulating oligosaccharides in tissue were thus identical in bovine and caprine beta-mannosidosis; however, the source of the novel oligosaccharides remains to be determined.