title: Plasmodium falciparum: characterization of a 33-kDa soluble antigen.
abstract: A 33-kDa soluble antigen identified in the culture supernatant by patient serum and monoclonal antibodies was present in rings, trophozoites, schizonts, and merozoites of Plasmodium falciparum. The antigen which is released into the culture supernatant by growing parasites was also observed in the host cells of trophozoites and schizonts and could be localized on the host cell surface. Its specificity for the surface of trophozoites and schizonts was observed to decrease with increased duration without subculture. The antigen could then be detected on the surface of noninfected erythrocytes. The antigenicity of the 33-kDa antigen was destroyed by heating at 65 degrees C. Monoclonal and polyclonal specific antibodies weakly inhibited parasite growth in vitro. The antigen was present in both knob positive and knob negative parasites in all the P. falciparum isolates tested.
authors: Department of Protozoology, Osaka University, Japan.
authors: M I
authors: MI
authors: Ramos
authors: Y
authors: Y
authors: Omata
authors: M
authors: M
authors: Igarashi
authors: T
authors: T
authors: Nakabayashi
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000913:Antibodies, Protozoan / Q000276:immunology; D000953:Antigens, Protozoan / Q000032:analysis* / Q000276:immunology; D000954:Antigens, Surface / Q000032:analysis / Q000276:immunology; D005591:Chemical Fractionation; D004591:Electrophoresis, Polyacrylamide Gel; D000939:Epitopes / Q000276:immunology; D005455:Fluorescent Antibody Technique; D006358:Hot Temperature; D006801:Humans; D006825:Hybridomas; D007106:Immune Sera / Q000276:immunology; D015151:Immunoblotting; D007526:Isoelectric Point; D010447:Peptide Hydrolases / Q000378:metabolism; D010963:Plasmodium falciparum / Q000276:immunology*; D011233:Precipitin Tests
chemical_list: D000911:Antibodies, Monoclonal; D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D000954:Antigens, Surface; D000939:Epitopes; D007106:Immune Sera; D010447:Peptide Hydrolases