EXTRACTION, PURIFICATION AND CHARACTERIZATION OF PAPAIN ENZYME (EC 3.4.22.2) FROM THE LEAVES OF CARICA PAPAYA

Abstract

Papain (EC 2.4.22.2) is a globular protein family consisting of a single polypeptide chain with three disulfide bridges and sulfuhydryl group necessary for proteolytic activity; it is an enzyme of Carica papaya. The aim of this study is to extract, purify and characterize papain enzyme (EC 2.4.22.2) from the leaves of Carica papaya. Papain enzymes from Carica papaya was purified in a 3-step purification using NH4(SO4)2 (70%), DEAE-Cellulose column chromatography and Sephadex G-25 column chromatography to achieve different purification folds, as different the fractions of the various peaks were pooled together. The effect of temperature, pH, substrate concentration and various concentrations of Mg2+ concentrations on different casein concentration was determined on the activity of the enzyme in the various pools. The findings from this study shows that purified papain enzyme from Carica papaya has optimum active from 50°C - 59°C and pH 4.5 – 6.6. Its activity is generally enhanced by addition of Mg2+. However, the enzyme is best activated at a concentration of 10mM of Mg2+ . The Km values for the papain enzymes ranges from 1.47mg/ml – 8.70mg/ml and the Vmax value of the enzyme ranges from 0.042µmol/ml/min – 0.4167µmol/ml/min. The values of the parameters obtained from this study could be put to use by the industry in the production of papain and also for household and medical use in storing the product.