Aim: Study system of activation of plasminogen in Vibrio cholerae.
Materials and methods: 75 strains of V. cholerae of various origins were used in the study. Plasminogen was isolated from human plasma by using affinity chromatography on L-lysine sepharose, alpha-enolase activity was determined by a direct method assuming transformation of 2-phosphoglycerate into phopshoenolpyruvate. Vibrios were destroyed by ultrasound disintegrator to isolate membrane Omp protein, intact cells were discarded by centrifugation and cell lysate was centrifugated for 1 hour at 105000 g. The precipitate was solubilized in buffer with 1% triton X-100 and passed through a column with DE-52 cellulose.
Results: Vibrio cholerae O1 and O139 strains isolated from clinical specimens and water samples from open water bodies had the ability to bind by using alpha-enolase and transform human plasminogen into plasmin under the effect of outer membrane protein OmpT A protein with molecular weight around 40 kDa had proteolytic activity with a wide specter of substrate specificity, degraded fibrin, gelatin, collagen, protamine and activated plasminogen. Computer analysis showed that OmpT protein of cholera vibrion had a low degree of relation with Enterobacteriaceae omptins.
Conclusion: The study carried out showed that vibrios have a system of activation of plasminogen that includes at least alpha-enolase and OmpT membrane protein. OmpT protein is assumed to belong to a new class of porins of Vibrionaceae family and its enzymatic activity may play a significant role in pathogenesis of infection.