Structure of a ganglioside with Cad blood group antigen activity.
The Cad antigen is a rare erythrocyte blood group antigen expressed on both sialoglycoprotein and ganglioside structures. It is related both serologically and biochemically to the Sda blood group antigen expressed on over 90% of Caucasian erythrocytes. We reported previously that Cad erythrocytes contain a novel ganglioside that binds Helix pomatia lectin and inhibits human anti-Sda antibody. We have now purified the Cad ganglioside and determined its structure. The ganglioside contained Glc-Gal-GlcNAc-GalNAc-NeuAc in a molar ratio of 1.00:1.94:0.95:0.93:1.05. Its chromatographic mobility was between that of GM1 and GD3. After treatment with beta-hexosaminidase (human placenta Hex A), the product migrated with 2-3-sialosylparagloboside (IV3NeuAcnLc4OseCer), it no longer bound H. pomatia lectin, and it acquired the ability to bind an antibody to sialosylparagloboside. Treatment of this material with neuraminidase (Vibrio cholerae) yielded a product with the mobility of paragloboside (nLc4OseCer) that bound monoclonal antibody 1B2, which is specific for terminal N-acetyllactosaminyl structures. Treatment of the Cad ganglioside with Arthrobacter ureafaciens neuraminidase yielded a product reactive with monoclonal antibody 2D4, which is specific for terminal GalNAc beta (1-4)Gal structures. These data provide strong evidence that the Cad ganglioside structure is GalNAc beta (1-4)[NeuAc alpha (2-3)]Gal beta (1-3)Gal beta (1-4)GlcCer. 1H NMR analysis also supports the conclusion that the terminal GalNAc is linked beta (1-4) to Gal. High-performance thin-layer chromatographic ganglioside patterns from three blood group Cad individuals showed a direct correlation between the quantity of Cad ganglioside and the strength of Cad antigen expression on the erythrocytes, as measured by hemagglutination.(ABSTRACT TRUNCATED AT 250 WORDS)
Gillard
B K
BK
Department of Medicine, Baylor College of Medicine, Houston, Texas 77030.
Blanchard
D
D
Bouhours
J F
JF
Cartron
J P
JP
van Kuik
J A
JA
Kamerling
J P
JP
Vliegenthart
J F
JF
Marcus
D M
DM
D001789:Blood Group Antigens; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002241:Carbohydrates / Q000032:analysis; D004912:Erythrocytes / Q000276:immunology; D005732:Gangliosides / Q000097:blood* / Q000302:isolation & purification; D006028:Glycosphingolipids / Q000097:blood / Q000302:isolation & purification; D006801:Humans; D008969:Molecular Sequence Data; D012016:Reference Values
D001789:Blood Group Antigens; D002241:Carbohydrates; D005732:Gangliosides; D006028:Glycosphingolipids