Efficient expression of the mosquito larvicidal binary toxin gene from Bacillus sphaericus in Escherichia coli.
The binary toxin gene encoding BinA (42 kDa) and BinB (51 kDa) from Bacillus sphaericus strain 2297 was cloned and expressed in E. coli. Low expression level was found when both proteins were expressed from a single operon. High expression was observed when the gene encoding an individual protein was placed downstream of the T7 promoter. The expression level of BinB was not different when expressed alone (non-fusion) or as a fusion form with T7 peptide (T7-BinB). Both forms of BinB were equally stable. Unlike BinB, the non-fusion form of BinA was less stable than T7-BinA. The mosquito larvicidal test showed that BinA or BinB alone was not toxic to mosquito larvae, but high toxicity was found when both BinA and BinB were applied. The results suggest that a short peptide of T7 linked to the N-terminus of either BinA or BinB does not affect their toxicity, but may make the toxin, especially BinA, more stable.
Promdonkoy
Boonhiang
B
National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, 113 Phaholyothin Road, Klong 1, Klong Luang, Pathumthani 12120, Thailand. boonhiang@biotec.or.th
Promdonkoy
Patcharee
P
Audtho
Mongkon
M
Tanapongpipat
Sutipa
S
Chewawiwat
Namchai
N
Luxananil
Plearnpis
P
Panyim
Sakol
S
D000818:Animals; D001427:Bacterial Toxins / Q000096:biosynthesis* / Q000235:genetics* / Q000633:toxicity; D003001:Cloning, Molecular; D003465:Culex / Q000187:drug effects* / Q000254:growth & development*; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics*; D015870:Gene Expression; D015151:Immunoblotting / Q000379:methods; D007306:Insecticides / Q000378:metabolism / Q000633:toxicity; D007814:Larva / Q000254:growth & development; D009876:Operon; D010572:Pest Control, Biological / Q000379:methods; D021122:Protein Subunits / Q000096:biosynthesis / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000235:genetics / Q000633:toxicity; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000633:toxicity; D014169:Transformation, Bacterial
D001427:Bacterial Toxins; D007306:Insecticides; D021122:Protein Subunits; D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins; C046134:binB protein, Bacillus sphaericus