Effect of indigenous legumes protease inhibitor proteins on Helicoverpa armigera

The proteins were isolated from the seeds of forty-nine cultivated legumes varieties belong to six genotypes (Mungbean, Pigeonpea, Soyabean, Chickpea, Pea and Lentil). The proteins were screened for the presence of protease inhibitor activity specific to Helicoverpa armigera larval mid gut proteases. The inhibitory units in seed extracts ranged from 6.20 U/mg of protein in chickpea cv Pusa-Pragati to 76.70 U/mg of protein in Soyabean cv Pusa-20. The crude extracts of selected varieties of Mungbean, Chickpea and Pigeonpea were subjected to ammonium sulphate fractionation examined for their specificity to gut proteases. In 40–80% ammonium sulphate fraction of cv Pusa- Vishal of Mungbean showed as 185.9 U/mg, in cv Pusa-33 of Pigeonpea as 180.43 U/mg and in Chickpea cv Pusa-372 it was found as 177.02 U/mg. The 40–80% fraction of Pigeon pea cv Pusa -33 also showed the pH and temperature stability. The stability was up to 20 minutes on pH 6.5 at temperature 90°C.