Purification, inhibitory properties, amino acid sequence and identification of the reactive site of a new serine proteinase inhibitor from oil-rape (itBrassica napus) seed (original) (raw)

Serine proteinase inhibitors, produced by plants, inhibiting protein digestion in herbivorous insects, can be used as one of the best ecofriendly IPM tactics. In this context, laboratory assay was conducted to identify the potential source of serine proteinase inhibitors from the seeds of 38 plant species corresponding to nine families. Among them, extracts from 20 species exhibited both trypsin and chymotrypsin inhibitory activity (TIA and CIA respectively) and 15 plant species possess TIA. The maximum TIA [9878 TIU (Trypsin Inhibitory Unit) g-1 of seed] was observed in Momordica balsamina seed extract. Erythrina variegata was found to possess both TIA (2737 TIU g-1 of seed) and CIA (2800 CIU Chymotrypsin Inhibitory Unit g-1 of seed). Seeds of two species may be utilized as a potential source of proteinase inhibitor in insect control programme. These presence of trypsin inhibitory activity in M. balsamina is reported for the first time.