Purification and characterization of thermoactive serratiopeptidase from Serratia marcescens AD-W2

Serratiopeptidase is a proteolytic enzyme extensively used as an anti-inflammatory and analgesic drug. Present work reports a thermoactive serratiopeptidase from Serratia marcescens AD-W2, a soil isolate from the North-Western Himalayan region of India. The extracellular metalloprotease has been purified by a simple two-step procedure resulting in a specific activity of 20,492 Units/mg protein with 5.28-fold purification. The molecular mass of the metalloprotease, as determined by SDS-PAGE was similar to 51 kDa. The purified serratiopeptidase presented optimum activity at pH 9.0, temperature 50 degrees C and stability in wide pH and temperature range. Critical temperature of 50 degrees C confirmed the thermoactivity of the purified serratiopeptidase. The kinetic studies of the purified serratiopeptidase revealed V-max and K-m of 57,256 Units/mL and 1.57 mg/mL, respectively, for casein. The purified serratiopeptidase from S. marcescens AD-W2 was found to be 100% identical to serralysin from Serratia marcescens ATCC 21074/E-15. The catalytic domain comprising of Zn coordinated with three histidine residues (His192, His196, His202), along with glutamate (Glu193) and tyrosine (Tyr232) residues, further confirmed that the purified protein is identical to serralysin.

Automated summary

This study reported a thermoactive serratiopeptidase from Serratia marcescens AD-W2, a soil isolate from the North-Western Himalayan region of India, which was purified with a specific activity of 20,492 Units/mg protein. The purified enzyme showed optimum activity at pH 9.0 and 50 degrees C, with stability in a wide range of pH and temperature. The identification of the enzyme as serralysin from Serratia marcescens ATCC 21074/E-15 was confirmed through molecular characterization.