International Research Journals

Research Article - International Research Journal of Plant Science ( 2021) Volume 12, Issue 5

Purification and characterization of a new cysteine protease from thevetia peruviana (pers.) merr.


Received: 01-Jun-2021, Manuscript No. IRJPS-21-32774; Reviewed: 15-Jun-2021 Published: 22-Jun-2021, DOI: http:/


A new cysteine protease was purified from the latex of Thevetia peruviana (Pers.) Merr. to electrophoretic homogeneity by a procedure involving pre-treatment of the latex followed by DEAE-cellulose chromatography. The purified protease was found to be a homodimeric protein with a native molecular weight of 36 kDa. The enzyme acting on azocasein as its substrate had a specific activity of 71 units/ mg protein, and it exhibited hyperbolic kinetics with Km and Vmax values of 26.7 µM and 2.23 units/mL respectively. The enzyme was also characterized by optimum pH of 6, optimum temperature of 50°C, and T½ of 64°C. Further, specific inhibitory studies revealed the enzyme to be a cysteine protease, and the enzyme exhibited fibrinolytic activity. Peptide mass fingerprinting analysis showed that the protease was not identical with any protein characterized earlier.