Preliminary characterization of a protease purified from a strain of Pseudomonas aeruginosa

The replication of Pseudomonas aeruginosa in bronchial secretions may not be as important as the production of extracellular enzymes, which are believed to play an important role in the pathogenesis of diseases due to this microorganism. There are experimental correlations between the ability to produce proteases and virulence and treatment of bacteria with subinhibitory concentrations of antimicrobial agents frequently suppresses the production of extracellular enzymes. We purified by ammonium sulphate precipitation, DEAE chromatography and ultrafiltration an enzymatic standard containing an extracellular protease suitable for use in investigations of the role of these enzymes as virulence factors. In this article we reported some physicochemical properties as the pH optimum, the temperature stability and the effect of metal salts, chelating and reducing agents on proteolytic activity.