Cloning and characterization of a cytolytic and mosquito larvicidal delta-endotoxin from Bacillus thuringiensis subsp darmstadiensis
Autor(es): Promdonkoy, B; Chewawiwat, N; Tanapongpipat, S; Luxananil, P; Panyim, S
Resumo: The cytolytic delta-endotoxin gene from Bacillus thuringiensis subsp. darmstadiensis was amplified from genomic DNA by PCR by using primers designed from the sequence of cyt2Aa1 gene of B. thuringiensis subsp. kyushuensis. DNA sequence analysis revealed an open reading frame translating to a 259-amino acid sequence. The cloned gene was designated cyt2Aa2. This gene was highly expressed in Escherichia coli as inclusion bodies that could be solubilized in 50 mm Na2CO3, pH 10.5. Activation of the solubilized protoxin by proteinase K (1% wt/wt, proteinase K/protoxin) yielded the active fragment of about 23 kDa. Cyt2Aa2 showed high hemolytic activity against sheep erythrocytes (hemolytic end-point 0.25 mug/ml) and was toxic to Culex quinquefasciatus and Aedes aegypti larvae (LC50 0.5-1.0 mug/ml).
Palavras-Chave: Pesticidal crystal proteins; Nucleotide - Sequence; Escherichia - Coli; Cyt gene; Israelensis; Mechanism; Identification; Medellin; Strains; Toxin
Imprenta: Current Microbiology, v. 46, n. 2, p. 94-98, 2003
Identificador do objeto digital: 10.1007/s00284-002-3823-5
Descritores: Aedes aegypti - DNA
Data de publicação: 2003
