Cloning and Expression of Beta Subunit Gene of Phycocyanin From Spirulina platensis in Escherichia coli

Background: C-Phycocyanin (C-PC) from blue-green algae such as Spirulina has been reported to have various pharmacological characteristics, including anti-inflammatory and anti-tumor activities. Recombinant B-subunit of C-PC (C-PC/B) is an inhibitor of cell proliferation and an inducer of cancer cell apoptosis. Objectives: Since C-PC/B has a big potential to be used as a promising cancer prevention or therapy agent, the purpose of this study was to clone and express Spirulina platensis cpcB gene in a bacterial expression system. This is a significant step for the production of this compound. Materials and Methods: The cpcB gene was amplified using specific primers and cloned in a bacterial expression vector, namely pET43.1a+. Gene expression of cpcB was analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and the dot blotting technique. Results: The SDS-PAGE analysis and dot blotting confirmed the production of recombinant C-PC/B in the bacterial expression system. Over-expression of cpcB gene was optimized in induction by 1 mM Isopropyl-B-D-Thiogalactoside (IPTG), after four hours of inoculation at 30°C. Conclusions: Over-expression of the synthetic CPC/B protein in the bacterial system (Escherichia coli BL-21) showed that E. coli can be used as a basis for further research to produce this desired protein in large quantities.