Characterization of recombinant protein ferritin from Pyropia yezoensis (rPyFer) and its biological activities

Ferritins are iron-binding proteins that are basically participated in iron storage, detoxification, and immune response. In the present study, ferritin gene from the marine red algae Pyropia yezoensis was cloned into a pET21d expression vector. High-efficiency transformation was performed in Escherichia coli BL21, the recombinant protein was expressed by induction with 0.1 mM isopropyl-β-D-thiogalactoside and purified via ammonium sulfate precipitation, anion exchange and size exclusion chromatography. The purified recombinant ferritin from P. yezoensis (rPyFer) was characterized and analyzed for its antimicrobial activity against both Gram-negative and Gram-positive bacterial cultures and exhibited significant antibacterial activity against Gram-positive cultures. The recombinant protein was also analyzed for its iron-uptake and radical-scavenging activities; rPyFer exhibited significant iron-uptake activity at low concentrations, and its radical-scavenging activity increased in a dose-dependent manner. This research will contribute to the development of new therapeutic proteins from marine algae.