Identification of Antibacterial Activity of Hepcidin From Antarctic Notothenioid Fish

Mingli Liu; Ruiqin Hu; Wenhao Li; Wenyi Yang; Qianghua Xu; Liangbiao Chen

doi:10.3389/fmicb.2022.834477

Identification of Antibacterial Activity of Hepcidin From Antarctic Notothenioid Fish

Front Microbiol. 2022 Apr 12:13:834477. doi: 10.3389/fmicb.2022.834477. eCollection 2022.

Authors

Mingli Liu^{1

2}, Ruiqin Hu^{1

2}, Wenhao Li^{1

2}, Wenyi Yang^{1

2}, Qianghua Xu^{1

2}, Liangbiao Chen^{1

2}

Affiliations

¹ Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai, China.
² International Research Center for Marine Biosciences, Ministry of Science and Technology, Shanghai Ocean University, Shanghai, China.

Abstract

Hepcidin is a small peptide composed of signal peptide, propeptide, and the bioactive mature peptide from N terminal to C terminal. Mature hepcidin is an antibacterial peptide and iron regulator with eight highly conserved cysteines forming four intramolecular disulfide bonds, giving it a β sheet hairpin-like structure. Hepcidin homologs are found in a variety of vertebrates, especially fish, and their diversity may be associated with different habitats and different levels of pathogens. Dissostichus mawsoni, an Antarctic notothenioid fish that lives in the coldest water unlike most places of the world, with at least two hepcidin variants with eight cysteines. We confirmed the formation process of activated mature hepcidins from D. mawsoni in Chinese hamster ovary (CHO) cell line, obtained recombinant hepcidin protein from prokaryotes, and characterized its binding ability and antibacterial activity against varying bacteria. The expression of hepcidin in CHO cell line showed that the prepropeptide of Dmhep_8cysV1 and Dmhep_8cysV2 cleavage into smaller mature peptide. The antibacterial assay and flow cytometry showed that Dmhep_8cysV1, Dmhep_8cysV2, and Drhep bound to different bacteria and killed them with different minimum inhibitory concentration. These data suggest that hepcidin plays an important role in the innate immunity of D. mawsoni and is of great value in improving resistance to pathogens.

Keywords: Antarctic notothenioid fish; antibacterial activity; antibacterial peptide; hepcidin; recombinant protein.