Cloning and expression of s lysostaphin enzyme gene in WB600.

Lysostaphin is a glycylglycine endopeptidase, secreted by , capable of specifically hydrolyzing pentaglycine crosslinks present in the peptidoglycan of the cell wall. In this paper, we describe the cloning and expression of the lysostaphin enzyme gene in WB600 host using pWB980 expression system. Plasmid pACK1 of was extracted using the alkaline lysis method. Lysostaphin gene was isolated by PCR and cloned into pTZ57R/T-Vector, then transformed into DH5α. The amplified gene fragment and uncloned pWB980 vector were digested using I and І enzymes and purified. The restricted gene fragment was ligated into the pWB980 expression vector by the standard protocols, then the recombinant plasmid was transformed into WB600 using electroporation method. The recombinant protein was evaluated by the SDS-PAGE method and confirmed by western immunoblot. Analysis of the target protein showed a band corresponding to 27-kDa r-lysostaphin. Protein content was estimated 91 mg/L by Bradford assay. The recombinant lysostaphin represented 90% of its maximum activity at 40 °C and displayed good thermostability by keeping about 80% of its maximum activity at 45 °C. Heat residual activity assay of recombinant lysostaphin demonstrated that the enzyme stability was up to 40 °C and showed good stability at 40 °C for 16 h incubation.