Antigenicity of the carbohydrate moiety of ganglioside GM3 having 3-O-acetyl ceramide.
To elucidate the effect of a modification of ceramide on antigenicity of the carbohydrate of ganglioside, the reactivity of O-acetyl GM3 having 3-O-acetyl ceramide, which has been characterized as a glioma-related ganglioside, with monoclonal antibody M2590 was examined in comparison to that of non-acetylated GM3, by means of quantitative enzyme-linked immunosorbent assay, TLC-immunostaining and liposome immune lysis assay. In all these assay systems, O-acetyl GM3 showed less activity than GM3 as follows: GM3 was detected till 0.1 nmol in TLC-immunostaining, whereas O-acetyl GM3 could not be detected even at 0.25 nmol; the GM3 reaction was approximately twofold that of O-acetyl GM3 at each diluted point in the enzyme-linked immunosorbent assay; and 20% of the liposomes containing GM3 were lysed at 6 mol%, while liposomes containing O-acetyl GM3 did not lyse at that concentration. The lesser antigenicity of the sugar moiety of O-acetyl GM3 could be ascribed to the presence of an acetyl group in the ceramide at the 3-position of sphingosine.
Daino
T
T
Department of Chemistry, Sapporo Medical University School of Medicine, Japan.
Tsuchihashi
K
K
Kashiwagi
M
M
Yachida
Y
Y
Akino
T
T
Gasa
S
S
D002518:Ceramides / Q000737:chemistry / Q000276:immunology*; D000939:Epitopes / Q000276:immunology; D005679:G(M3) Ganglioside / Q000737:chemistry / Q000276:immunology*; D007118:Immunoassay; D008081:Liposomes
D002518:Ceramides; D000939:Epitopes; D005679:G(M3) Ganglioside; D008081:Liposomes