The increased Expression of Lipl۴۱ Outer Membrane Protein in Pathogenic Leptospires in combination with Lep Protein: potential application for immunoassay improvement

Background and Aim : Leptospirosis is an important worldwide zoonotic disease that is caused by Leptospira spirochaetes. It is generally found in humid tropical and subtropical regions. Unfortunately, because of the variety of clinical symptoms, its detection has many restrictions. LipL۴۱ is among the most abundant outer membrane proteins in Leptospira and only found in pathogenic species. A small gene called lep is placed very close to lipl۴۱ gene on the bacterial chromosome. Lep is a small chaperone protein which acts as a partner to increase expression of Lipl۴۱. In the present study, the expression and purification of LipL۴۱-Lep combined protein among predominant pathogenic isolates in Iran was accomplished in a prokaryotic system. Methods : All available protein sequences were compared and analyzed using bioinformatics tools from NCBI databases. Recombinant LipL۴۱-Lep protein was produced using the pET۳۲a+ vector and expressed in Escherichia coli BL۲۱ (DE۳) competent cells. It was purified by denaturation and confirmed by western blotting.Results : The protein was successfully expressed in BL۲۱ (DE۳) and purified. SDS-PAGE results revealed that the full-length ۶۰kD fusion protein was induced by IPTG and present in the insoluble form.Conclusion : The results showed that when Lipl۴۱ is combined with Lep, the level of its expression is increased compared to when it is alone. This recombinant combined protein can be used as a potential application for immunoassay improvement.

Keywords:

Pathogenic Leptospires , LipL۴۱-Lep recombinant combined protein , Expression , Leptospirosis