Isolation, purification and characterization of a pH tolerant and temperature stable proteinaceous protease inhibitor from marine Pseudomonas mendocina

Potential Anticoagulant Activity of Trypsin Inhibitor Purified from an Isolated Marine Bacterium Oceanimonas Sp. BPMS22 and its Kinetics

Protease inhibitors control major biological protease activities to maintain physiological homeostasis. Marine bacteria isolated from oligotrophic conditions could be taxonomically distinct, metabolically unique, and offers a wide variety of biochemicals. In the present investigation, marine sediments were screened for the potential bacteria that can produce trypsin inhibitors. A moderate halotolerant novel marine bacterial strain of Oceanimonas sp. BPMS22 was isolated, identified, and characterized. The effect of various process parameters like salt concentration, temperature, and pH was studied on the growth of the bacteria and production of trypsin inhibitor. Further, the trypsin inhibitor was purified to near homogeneity using anion exchange, size exclusion, and affinity chromatography. The purified trypsin inhibitor was found to competitively inhibit trypsin activity with an inhibition coefficient, K_i, of 3.44 ± 0.13 μM and second-order association rate constant, k_ass, of 1.08 × 10³ M^-1 S^-1. The proteinaceous trypsin inhibitor had a molecular weight of approximately 30 kDa. The purified trypsin inhibitor showed anticoagulant activity on the human blood samples.