Extraction, purification, and activity of protease from the leaves of Moringa oleifera

Background: Proteases cleave proteins, thereby providing essential amino acids for protein synthesis, and degrade misfolded and damaged proteins to maintain homeostasis. Proteases also serve as signaling molecules, therapeutic agents and find wide applications in biotechnology and pharmaceutical industry.  Plant-derived proteases are suitable for many biomedical applications due to their easy availability and activity over a wide range of pH, temperature, and substrates. Moringa oleifera Lam (Moringaceae) is a very common food plant with medicinal property and geographically distributed in tropical countries. Here, we isolate proteases from the leaves of Moringa oleifera and characterize its enzymatic activity. Methods: Proteases were isolated from the aqueous leaf extract of Moringa oleifera by ammonium sulfate precipitation and purified by ion exchange chromatography. Subsequently, the enzyme kinetics was determined using casein as a substrate and calibrated over different pH and temperature range for maximal activity. Results: We obtained purified fraction of the protease having a molecular weight of 51 kDa. We observed that for the maximal caseinolytic activity of the protease, a pH of 8 and temperature of 37ºC was found to be most effective. Conclusion: The plant-derived proteolytic enzymes are finding increasing clinical and industrial applications. We could extract, purify and characterize the enzymatic activity of proteases from the leaves of Moringa oleifera. Further molecular characterization, substrate specificity and activity of the extracted protease are required for determining its suitability as a proteolytic enzyme for various applications.