Blood group type glycosphingolipids of human kidneys. Structural characterization of extended globo-series compounds

Abstract

Blood group type glycosphingolipids present in kidneys of blood group A and B human individuals have been isolated and structurally characterized by mass spectrometry, proton NMR spectroscopy, degradation studies and by their reactivity with various monoclonal antibodies and Escherichia coli bacteria. The two major complex glycolipids present in the blood group A and B kidneys were globopentaosylceramide (IV3Gal beta-Gb4Cer) and the X pentaglycosylceramide (III3Fuc alpha-nLc4Cer). The major blood group A glycolipid in the blood group A kidneys was based on the type 4 chain (globo-series). There were also small amounts of the type 2 chain and trace amounts of the type 1 and type 3 chain based A glycolipids. In addition, the blood group H type 4 chain structure was present together with Le(a) and Le(b) compounds. In the blood group B kidneys, the major B glycolipids were monofucosylated hexa- and octaglycosylceramides, where the former were based on the type 2 carbohydrate chain. The blood group B type 4 chain heptaglycosylceramide was found to be a minor component making up only about 1% of the total blood group B structures.