Biological Activity of Serine Protease Inhibitor Isolated from the Seeds of Phaseolus vulgaris

Abstract

Seed flour extract of local common bean cultivar Baspa inhibited gut proteases of Spodoptera litura Fab. The inhibitor protein was purified by ammonium sulphate precipitation and gel filtration chromatography. Freshly laid eggs of Pieris brassicae L. treated with 220-µg inhibitor protein showed 89.60% reduction and delay in hatching by 2 days as compared to control. Feeding neonate larvae of P. brassicae on cabbage leaf discs coated with inhibitor protein (79.25 and 118.88 µg) for 6 days resulted in 50 and 89% larval mortality and reduction in larval growth by 20.77 and 48.47% as compared to untreated control. The treated larvae (118.88 µg) shifted on untreated leaf discs showed mortality after 3 days. However, the growth of treated larvae (79.25 µg) fed on untreated leaf discs further decreased to 45.17% showed delayed pupation, deformed pupa formation and no adult emergence in contrast to control larvae.