Expression and purification of the active soluble form of Bacillus sphaericus binary toxin for structural analysis

► We produced recombinant binary toxin (BinA and BinB components) in soluble forms in Escherichia coli. ► The soluble BinA and BinB showed higher toxicity against Culex mosquito larvae than that of the inclusion form. ► The proteolytic products of BinA and BinB form a complex in solution. ► Secondary structures of BinA and BinB determined by far-UV circular dichroism were proposed to adopt mainly beta structures.