Fibrinogen and mucin binding activity of EF0737, a novel protein of Enterococcus faecalis

Background and Objectives: Enterococcus faecalis is the leading cause of several human infections. This opportunist pathogen expresses surface components that have various functions in the infection process including bacterial adhesion, lytic activity, and induction of host immune responses. EF0737, a novel cell wall associated protein, may play an important role in pathogenesis of E. faecalis, based on our experiments. This study was conducted to clone and express EF0737 and demonstrate its interaction with biotinylated plasma proteins and patients’ sera. Materials and Methods: The full length of ef0737 gene was cloned in pTZ57R/T cloning vector and subcloned in pET21a expression vector. Recombinant protein expressed in Escherichia coli Origami (DE3) was confirmed by western blot technique, using anti-His tagged monoclonal antibodies, and was then purified. Interaction of the recombinant protein with plasma proteins and patients’ sera were examined by western blot. Results: The ef0737 gene was successfully cloned and expressed in E. coli Origami host. Binding activity was observed between the purified EF0737 recombinant protein and fibrinogen and mucin among other plasma proteins. Moreover, reaction was also observed between the purified product and sera obtained from patients diagnosed with E. faecalis infection. Conclusion: The observed reactions between EF0737 and fibrinogen, mucin and patients’ sera suggest that EF0737 may play important role in pathogenesis of infections caused by E. faecalis. However, more comprehensive characterization of this novel protein may provide better understanding of host pathogen interaction.