Identification of a second cytotoxic protein produced by Bacillus thuringiensis A1470

Biotechnol Lett. 2013 Nov;35(11):1889-94. doi: 10.1007/s10529-013-1275-6. Epub 2013 Jun 26.


Bacillus thuringiensis A1470 produces multiple proteins with similar molecular masses (~30 kDa) with cytotoxicity against human cell lines. One that was previously identified, parasporin-4, is a β-pore-forming toxin. The N-terminal sequence of a second cytotoxic protein was identical to a partial sequence of parasporin-2 produced by B. thuringiensis A1547. PCR was performed on total plasmid DNA from A1470 by using primers for parasporin-2 to amplify a gene which was then cloned. The cloned gene differed from A1547 parasporin-2 by 8 bp and the predicted protein differed by four amino acids. The gene was expressed in Escherichia coli, and the cytotoxic activities of the recombinant protein against four human cell lines (MOLT-4, Jurkat, HeLa, and HepG2) were similar to those of A1547 parasporin-2. We then confirmed that the A1470 strain simultaneously produces parasporin-2 and parasporin-4.

MeSH terms

  • Bacillus thuringiensis / genetics
  • Bacillus thuringiensis / metabolism*
  • Bacterial Toxins / genetics
  • Bacterial Toxins / metabolism*
  • Cell Line
  • Cloning, Molecular
  • Cytotoxins / genetics
  • Cytotoxins / metabolism*
  • DNA, Bacterial / chemistry
  • DNA, Bacterial / genetics
  • Escherichia coli / genetics
  • Gene Expression
  • Humans
  • Molecular Sequence Data
  • Plasmids
  • Recombinant Proteins / genetics
  • Recombinant Proteins / isolation & purification
  • Recombinant Proteins / toxicity
  • Sequence Analysis, DNA


  • Bacterial Toxins
  • Cytotoxins
  • DNA, Bacterial
  • Recombinant Proteins

Associated data

  • GENBANK/AB454419