Characterisation of tissue-specific oligosaccharides from rat brain and kidney membrane preparations enriched in Na+,K+-ATPase

The organ-specific nature of the glycosylation of Na+,K+-ATPase-enriched pr eparations from kidney and brain tissues has earlier been indicated by the use of lectin-staining techniques. Na+,K+-ATPase is ubiquitous and abundant , and subject to upregulation during cell-division and in certain pathologi cal conditions. Lectins specific for the different carbohydrates displayed by the Na+,K+-ATPases may, therefore, be useful carriers/mediators in tissu e-specific targeting. N-linked oligosaccharides purified from Na+,K+-ATPase -enriched preparations from rat brain and kidney were consequently characte rised in detail in this study using weak anion exchange and normal phase HP LC (combined with serial glycosidase digestions) and matrix-assisted laser desorption/ionisation mass spectrometry. The oligomannose series of glycans were most abundant in the brain tissue preparation and this contrasted wit h the renal-associated oligosaccharides that were dominated by families of tetra-antennary glycans (with/without a core fucose) with up to four lactos aminylglycan residues in either branched or linear formation.