Crinumin, a novel substitute of chymotrypsin, may control pancreatic insufficiency and inflammation: Purification and characterization

Crinumin, a glycosylated serine protease with chymotrypsin like catalytic specificity was purified from a medicinally important plant _Crinum asiaticum_ of family _Amaryllidaceae_. Ethno-botanical information and Pharmacological studies confirming about the presence of active bio- molecules in the _Crinum_ played crucial role in injury, inflamed joint, local pain and arthritis. Biomedical research suggests chymotrypsin was not only used as digestive aid but also helpful in the above disease. These findings support towards the crinumin may be the active bio-molecule. Crinumin shows activity over a wide range of pH (4.5-11.5 and optimum at 8.5), temperature (75 °C and optimum at 70 °C) and is also functional against chaotrophs, organic solvents, and detergents even after prolonged exposure. The molecular mass (67.7kDa), extinction coefficient (17.7) and isoelectric point (6.9) were also estimated. The denatured natural substrates, such as casein, azocasein, azoalbumin and haemoglobin were hydrolysed by crinumin with very high specific activity. The enzyme also showed amidolytic activity against synthetic substrates, N-succinyl-Phe-p-nitroanilide and α-leucine-pnitroanilide. The apparent Km, Vmax and Kcat values obtained from the Lineweaver–Burk plot were 5 × 104 μM, 0.316 μM/min and 0.73 with N-succinyl-L-phenylalanine-p-nitroanilide as substrate. The proteolytic activity of the enzyme is inhibited by PMSF but not by SBTI make it more special and useful than other serine proteases being used in the food industry. Easy and economic purification with high yield (33%), stability and activity in adverse conditions with chymotrypsin like functioning make it better among known chymotrypsin enzymes from different sources.