Cloning, expression and purification of recombinant prolysostaphin protein and evaluating its in vitro antistaphylococcal activity

Staphylococcusaureus causes a wide range of infections, from skin infections disseminated to systemic infections leading to organ failure and death. Drug resistance in this group of pathogens is a world-wide concern and needs the development of novel agents. Lysostaphin, an example of such a novel agents,is a bacteriocin secreted by Staphylococcussimulans to kill Staphylococcus aureus through proteolysis of the Staphylococcus cell wall.The aim of this study was to high level expression and in vitro evaluation of antistaphylococcal activity of recombinant prolysostaphinprotein under invitro conditions. In this experimental study, lysostaphin gene of Staphylococcussimulans was amplified by PCR method, then was cloned and expressed into the expression vector pET-32a. The expressed protein was purified by affinity- chromatography using (Ni-NTA) resin kit. The Study of antibacterial activity against a cell suspension of S. aureuswere was performed using turbidity assay. PCR and sequencing results showed the successful cloning of the target gene into the recombinant vector. The expression of protein was induced by IPTG and high concentration of the recombinant protein with antistaphylococcal activitywas purified using Ni-NTA resin. Our data showed that, the pET32a expression vector is a very efficient system for producing recombinant prolysostaphin protein in E.coli.