Partial Purification of Phytocystatin from Moringa oleifera lam

Background: Phytocystatins are plants cysteine protease inhibitors (CPIs) that are known for their numerous uses in medicine and biotechnology. Methods: Different extraction media which include, Sodium Hydroxide, Hydrochloric acid, Sodium Chloride, Sodium phosphate buffer and distilled Water were used to evaluate flower, leave, root, latex, and stem bark of Moringa oleifera for inhibitory activity against cysteine protease (Papain enzyme). The phosphate buffer extract with higher protease inhibitory activity was concentrated by cold acetone precipitation and further subjected to partial purification using ammonium sulphate fractionation and Hydrophobic chromatography on Phenyl Sepharose column. The molecular weight of partially purified protein was estimated by sodium dodecyl sulphate (SDS) polyacrylamide gel electrophoresis. Results: The extracts of Sodium phosphate buffer from the seeds of Moringa oleifera showed higher CPI activity of 11.23 units/mg protein. Cold acetone precipitated extract gave high yield of 94.6% protein with 60% inhibition of protease. The partially purified protein showed a fifty percent inhibitory concentration (IC50) of 1.22±0.3 mg/ml protein against the enzyme with 63% inhibition. An estimated molecular weight of 13.5kDa was obtained from electrophoretic analysis of partially purified protein. Conclusion: Moringa oleifera seeds could be a good source of low molecular weight protein Inhibitor of Cysteine protease and might be useful in biotechnology of traditional medicinal plants, in transgenic crops to arrest the negative pathogenic over expressions of cysteine proteases