Expression and Purification of the Recombinant Cytochrome P450 CYP141 Protein of Mycobacterium Tuberculosis as a Diagnostic Tool and Vaccine Production

Abstract

Background: Tuberculosis (TB) is regarded as a health problem worldwide, particularly in developing countries. Mycobacterium tuberculosis (M. tuberculosis) is the cause of this disease. Approximately two billion people worldwide are infected by M. tuberculosis and annually about two million individuals die in consequence. Forty million people are estimated to die because of M. tuberculosis over the next 25 years if the measures for controlling this infection are not extensively developed. In the vaccination field, Bacillus Calmette-Guerin (BCG) is still the most effective vaccine but it shows no efficacy in adult pulmonary patients. One of the other problems regarding TB is its appropriate diagnosis. Objectives: In this experimental study, the recombinant cytochrome P450 CYP141 protein of M. tuberculosis was expressed and purified to be used as a vaccine candidate and diagnostic purpose in subsequent investigations. Materials and Methods: The optimization of the cytochrome P450 CYP141 protein expression was evaluated in different conditions. Then, this protein was purified with a resin column of nickel-nitrilotriacetic acid and investigated via Sodium Dodecyl Sulfate Polyacrylamide Gel Electrophoresis (SDS-PAGE) and Western Blotting. Results: The highest expression of the cytochrome P450 CYP141 protein was obtained by the addition of 1 mM of isopropyl beta-D-1-thiogalactopyranoside (IPTG) to the bacterial culture grown to an optical density at 600 nm (OD600) of 0.6, 16 hours after induction. This protein was subsequently purified with a purification of higher than 80. The results of Western Blotting indicated that the purified protein was specifically detected. Conclusions: In this experimental study, for the first time in Iran the expression and purification of this recombinant protein was done successfully. This recombinant protein could be used as a vaccine candidate and diagnostic purpose in subsequent investigations.