About (20) Pseudomonas rogenosa isolate were experienced for their ability of protease production by calculating the diameter of lysis area after developing on skim milk agar medium (qualitatively ) and the results exhibited that only isolate no (5), was higher isolate for protease making of (26mm) of lysis area.
Then, the protein concentration also identified by Bradford method and it was found of 0.16 mg/ ml , then purification was done by using an ion- exchange chromatography with DEAE sephadex G- 100 column and the results showed the presence of 1 peak of enzyme with 50 Kd of molecular weight 2 peaks of other proteins . we tried to investigate the invitro Cytotoxic effect of purified enzyme against two human cancer lines, HeP2 (Human larynx epidermed carcinoma ) , RD ( Rabdo- Sarcoma ) , and one normal cell line Ref ( Rat embryonic fibroblast ) . The cancer and normal cells were treated with different concentrations of protease enzyme ranging from ( 0.05, 0.1, 0.2, 0.4,0.8and 0.16 mg/ml) then incubated for additional 48h at 37C0 and the results showed highest toxicity ( 80.28%) of protease enzyme on RD , moderate cytotoxicity (45.52%) on Hep andslight toxicity ( 37.12% ) on normal cell line (Ref) in a concentration (0.8mg/ml).
