Binding of Bacillus sphaericus binary toxin to a specific receptor on midgut brush-border membranes from mosquito larvae
Autor(es): Nielsenleroux, C; Charles, JF
Resumo: The presence of specific receptors for Bacillus sphaericus binary toxin on brush-border membrane fractions (BBMF) from Culex pipiens larvae midgut cells was demonstrated by an in vitro binding assay. Both activated and radiolabelled polypeptides from the 51-kDa and 42-kDa binary toxin of B. sphaericus 1593 specifically bound to BBMF. Direct binding and homologous competition experiments indicated a single class of B. sphaericus toxin receptors, with a dissociation constant (K(d)) of approximately 20 nM and a maximum binding capacity (B(max)) of approximately 7 pmol/mg BBMF protein. The sugars GalNAc, GlcNAc and N-acetyl neuraminic acid had no detectable inhibitory effect on toxin binding to C. pipiens BBMF. Binding experiments with the non-susceptible mosquito species Aedes aegypti failed to detect significant binding of B. sphaericus binary toxin to A. aegypti BBMF.
Palavras-Chave: Thuringiensis delta - Endotoxins; Butterfly pieris - Brassicae; Larvicidal toxin; Sequence -Analysis; Culicidae larvae; Proteins; Identification; Genes; Cells; Purification
Imprenta: European Journal of Biochemistry, v. 210, n. 2, p. 585-590, 1992
Identificador do objeto digital: 10.1111/j.1432-1033.1992.tb17458.x
Descritores: Aedes aegypti - Cell ; Aedes aegypti - Proteins
Data de publicação: 1992
