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

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 andEscherichia coli bacteria. The two major complex glycolipids present in the blood group A and B kidneys were globopentaosylceramide (IV³Gal-Gb₄Cer) and the X pentaglycosylceramide (III³Fuc-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. Abbreviations: for blood group glycolipid antigens the short hand designation stands for blood group—number of sugar residues—type of carbohydrate chain. Thus A-7-4 means a type 4 chain blood group A heptaglycosylceramide. The sugar types are abbreviated for mass spectrometry to Hex for hexose, HexNAc forN-acetylhexosamine and dHex for deoxyhexose.