Identification and Characterization of Plant Bioactive Peptides as Potential Biopesticides

Abstract

ABSTRACT newlineTotal 128 samples were screened for inhibitory activity in three concentrations i.e. equal, low and high (E:I ratio of 1:1; 1:2 and 2:1) and those which are capable of inhibiting even at lower concentrations were chosen for further studies. Three different concentrations were premixed with trypsin and loaded onto the gel, after few minutes of visual observation film was washed. X-ray film. Dot blot assay reveals Citrullus colocynthis, Ipomoea hederacea, Dryptes roxburghii, Cassia absus Showed inhibition in all three concentrations whereas Lepidium iberis, Piper nigrum, Pimpinella anisum showed inhibition at 1:3 concentrations. Spodoptera gut proteases (SGP) when pre-incubated with different inhibitors showed that Piper cubeba and Mucuna pruriens possess high inhibitory activity against the larval enzymes i.e. 56.84% and 56.59%. Pimpinella anisum, Citrullus colocynthis, Juniperus communis, Piper cubeba, Apium leptophyllum, Cassia absus Linn. Lowest activity was shown by Ipomoea hederacea Jacq. and Dryptes roxburghii. newlineCassia absus contain proteinacious-protease inhibitors showing inhibitions with SGP. Preliminary results suggest that the trypsin inhibitor was quite stable to heat for 30 minute. The optimum pH for the inhibitory activity is pH 7.7 indicates presence of Kunitz inhibitor type. The highest trypsin inhibitory activity was found at protein precipitated around 20% ammonium sulphate concentration. Gelatin embedded native PAGE of purified TI incubated independently with trypsin showed that the seeds contain multiple forms of TI. The molecular weights estimated of the three isoforms newlineof TI as determined by SDS-PAGE were ~30.3 kDa, ~19.6 kDA. and ~17.8kDa, 70 ug of partially purified protein causes 100% of trypsin inhibition. Thermal stability of C. absus inhibitor was assessed to check whether it can with stand high temperatures newline