Vitellogenin-derived fragment in embryos of Japanese flounder Paralichthys olivaceus with binding and bactericidal activities against an infectious bacterium via an interaction with saccharides

• Published in: Molecular immunology Vol. 142; pp. 76 - 82
• Main Authors: Tsutsui, Shigeyuki, Sato, Misaki, Miyashita, Masaki, Amano, Haruna, Maeda, Tomoki, Nakamura, Osamu
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.02.2022
• Subjects: Amino Acid Sequence; Animals; Anti-bacterial activity; Anti-Bacterial Agents - pharmacology; Edwardsiella tarda - drug effects; Edwardsiella tarda - growth & development; Egg Proteins - metabolism; Egg Proteins - pharmacology; Embryo; Enterobacteriaceae Infections - veterinary; Fish Diseases - drug therapy; Fish Diseases - microbiology; Fish Proteins - metabolism; Flounder - embryology; Flounder - microbiology; Japanese flounder Paralichthys olivaceus; Lectin; Maternal immunity; Microbial Sensitivity Tests; Ovum - cytology; Tandem Mass Spectrometry; Vitellogenin-derived product; Vitellogenins - metabolism; vLv; Lectin; Embryo; LvL; TBS; Pv; MIC; Vitellogenin-derived product; LC/Q-TOF-MS; Lv; EDTA; Anti-bacterial activity; Japanese flounder Paralichthys olivaceus; MBC; Maternal immunity; Vg; oLv; PAMPs; LvH
• ISSN: 0161-5890; 1872-9142
• DOI: 10.1016/j.molimm.2021.12.017

•Two Edwardsiella tarda -binding lectins were purified from the embryos of Paralichthys olivaceus.•One was lipovitellin heavy-chain (LvH), and the other was an N-terminal bit of LvH.•The latter showed strong bactericidal activity against E. tarda. Thirty- and 90-kDa proteins with binding ability to Edwardsiella tarda, a causative bacterium of Edwardsiellosis in fish, were purified from the embryo of Japanese flounder Paralichthys olivaceus. The proteins were isolated with affinity chromatography, in which the bacterium was used as a ligand and galactose, mannose, and ethylenediaminetetraacetic acid (EDTA) were used as elution agents, followed by gel filtration chromatography. N-terminal amino acid sequencing and liquid chromatography with quadrupole time-of-flight tandem mass spectrometry (LC/Q-TOF-MS) analysis revealed that the 90-kDa protein was lipovitellin heavy-chain (LvH), which is one of the proteolytically cleaved products of maternal vitellogenin (Vg) and represents the main precursor of the egg yolk in teleosts, and the 30-kDa protein was an N-terminal bit of LvH. On the other hand, Vg in the serum of the mother fish did not bind to E. tarda. While the 90-kDa protein did not show anti-bacterial activity, the 30-kDa protein strongly exhibited activity toward E. tarda, with a minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) below 0.06 μM, suggesting that the latter protein plays an important role during embryogenesis in the flounder. This is the first report showing that Vg-derived products have monosaccharides-binding activity and a fragment derived from LvH exhibits bactericidal activity.