title: Tetanus toxin interaction with human erythrocytes. I. Properties of polysialoganglioside association with the cell surface.
abstract: Human erythrocytes in suspension acquire gangliosides containing di- and trisialosyl residues added to the maintenance medium. This is reflected in the increased cell-associated sialic acid content and ability to bind 125I-labeled tetanus toxin. A salt-sensitive and a salt-insensitive ganglioside-mediated toxin-cell surface association is detected which is reduced after sialidase treatment of ganglioside-supplemented cells. The salt-insensitive ganglioside-cell association is saturable after 2 h incubation in 0.3 M mannitol buffer and has an optimum at pH 5. The association process is higher at 37 degrees C than at 4 degrees C, depends on cell density, and is considerably higher in metabolically active cells compared to lysed cells. Pretreatment of cells with trypsin decreases the salt-resistant toxin association with ganglioside-supplemented cells. In contrast, glutaraldehyde-fixed cells treated with trypsin and supplemented with gangliosides bind more toxin which is insensitive to salt. Ganglioside-mediated tetanus toxin binding to the intact erythrocyte membrane can be utilized as a model system for studying the role of glycolipids in membrane function.
mesh_terms: D002452:Cell Count; D002470:Cell Survival; D002855:Chromatography, Thin Layer; D004912:Erythrocytes / Q000378:metabolism*; D005732:Gangliosides / Q000378:metabolism*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D009439:Neuraminidase / Q000378:metabolism; D009994:Osmolar Concentration; D013696:Temperature; D013744:Tetanus Toxin / Q000378:metabolism*; D014357:Trypsin / Q000378:metabolism
chemical_list: D005732:Gangliosides; D013744:Tetanus Toxin; C033851:ganglioside, GD1b; D009439:Neuraminidase; D014357:Trypsin