CHARACTERIZATION OF LARVICIDAL TOXIN PROTEIN FROM BACILLUS-THURINGIENSIS SEROVAR JAPONENSIS STRAIN BUIBUI SPECIFIC FAR SCARABAEID-BEETLES

The delta-endo toxin proteins from Bacillus thuringiensis which kill t he larvae of various scarabaeid beetles such as Anomala cuprea, A. ruf ocuprea and Popillia japonica were purified by DEAE ion exchange chrom atography. A protein with a molecular size of 130 kDa was purified. Du ring the purification a minor peak was also detected which was estimat ed to be 67 kDa by SDS-PAGE. Both 130 and 67 kDa proteins showed larvi cidal activity against A. cuprea. The lethal concentration of the 130 kDa protein which killed 50% of the larvae tested (LC(50)) against A. cuprea was 2 mu g g(-1) compost. A comparison by SDS-PAGE of the V8 pr otease digestion pattern of the 130 and 67 kDa larvicidal proteins sho wed that proteolytic resistant core peptides of approximately 60 kDa m olecular size were resulted. The N-terminus amino acid sequence of the 130 and 67 kDa proteins was determined to be NH2-XXPNNQNEYEIIDAL and NH2-XSRNPGTFI, respectively, which is not identical to the sequence of CryIA, CryIB, CryIC and CryIII proteins.