Characterization of an Intracellular Protease from Pseudomonas Aeruginosa

An intracellular protease was extracted and purified from Pseudomonas aeruginosa by ion-exchange chromatography on DEAE-cellulose followed by CM–cellulose and rechromatography on DEAE-cellulose. The purified protease was found to be homogeneous as judged by polyacrylamide disc gel electrophoresis (PAGE). The molecular mass of the protease as determined by gel filtration on G-150 was about 48,000 and about 49,000 on SDS-PAGE. The enzyme is monomeric in nature. The purified protease is a glycoprotein with neutral sugar content of 0.6%. The Km value of the protease was found to be 0.48% against casein as substrate. The enzyme is stable up to 600C and showed maximum activity around 500C. The enzyme activity was affected with the changes of pH and the maximum proteolytic activity was observed at pH 8.0. The protease activity was inhibited in the presence of EDTA, Cu2+, Mn2+and Hg2+ whereas the presence of Ca2+, K+, Na+ and ascorbic acid enhanced the activity.