the cytoplasmic and periplasmic expression levels and folding of organophosphorus hydrolase enzyme in escherichia coli

Background: organophosphorus hydrolase (oph) is a type of organophosphate-degrading enzyme which is widely used in the bioremediation process.objectives: in this study, the periplasmic and cytoplasmic productions and the activity of recombinant oph in escherichia coli were investigated and compared using two pet systems (pet21a and pet26b).materials and methods: the sequence encoding the opd gene was synthesized and expressed in the form of inclusion body using pet21a-opd and in the periplasmic space in pet26b-opd.results: sodium dodecyl sulfate polyacrylamide gel electrophoresis (sds-page) analysis showed a band of about 37 kda with a maximum expression level at 30°c from pet21a-opd.however, the obtained results of the periplasmic space extraction of oph (pet26b-opd) showed a very weak band, while the cytoplasmic expression of oph (pet21a-opd) produced a strong protein band.conclusions: the activities studied by the production of pnp were determined by following the increase at 410 nm. the maximum pnp was produced at 30°c with an optical density of 10.62 in the presence of cytoplasmic expression of oph (pet21a-opd). consequently, our results suggest cytoplasmic expression system as an appropriate candidate with a high amount of oph in spite of inclusion body formation, which needs an additional refolding step.