Further evidence for the role of 26 kDa peptide as mosquito larvicidal principle of the crystalline delta endotoxin of Bacillus thuringiensis var israelensis

Separation of the toxic and non-toxic subunits of the crystals of B. thuringiensis var israelensis, in native gels has revealed that the toxic subunit contained predominantly 26 kDa peptide, while the non-toxic subunit was made up of 66 kDa and other larger molecular weight peptides. Tryptic digestion of the crystal proteins and their separation on a DEAE-cellulose column, resulted in the generation of a fraction with a 21 kDa peptide, exhibiting larvicidal and hemolytic activities and immunoreactive with the antiserum of 26 kDa peptide of the crystals. These results show that 26 kDa peptide is the active principle of the crystal.