title: Isolation and characterization of a novel antibacterial peptide derived from hemoglobin alpha in the liver of Japanese eel, Anguilla japonica.
abstract: We isolated and characterized a novel antibacterial peptide, AJHbα, derived from hemoglobin alpha in the liver of Japanese eel, Anguilla japonica. It with concentration of 11.30 μM exhibited stronger antibacterial activity against pathogenic bacterium 1 × 10(6) cell ml(-1)Edwardsiella tarda than other two bacteria. The extraction procedure for AJHbα included extraction with acetate acid, ultrafiltration, cation-exchange chromatography on HiTrap™ CM FF, reverse-phase liquid chromatography on Source 5R RPC and C18 RP-HPLC. MALDI-TOF MS suggested that the peptide had an observed molecular weight of 2388.05 Da. Its amino acid sequence determined by Edman degradation was similar to those of hemoglobin alpha chain in other fish by BLAST analysis. A complete N-terminal amino acid sequence of the AJHbα was FAHWPDLGPGSPSVKKHGKVIM corresponding to the cDNA sequence by RACE amplification. Its synthetic peptide had strong antibacterial activities against ten Gram-positive or negative bacteria. To our knowledge, AJHbα was the first identified fragment of hemoglobin alpha chain with strong antibacterial activity in fish.
authors.affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, Hubei Province, China.
authors.forename: Dong Ling
authors.initials: DL
authors.lastname: Zhang
authors.forename: Rui Zhang
authors.initials: RZ
authors.lastname: Guan
authors.forename: Wen Shu
authors.initials: WS
authors.lastname: Huang
authors.forename: Jing
authors.initials: J
authors.lastname: Xiong
mesh_terms: D000595:Amino Acid Sequence; D000811:Anguilla / Q000378:metabolism*; D000818:Animals; D000900:Anti-Bacterial Agents / Q000378:metabolism*; D001483:Base Sequence; D029941:Fish Proteins / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D055542:alpha-Globins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D029941:Fish Proteins; D055542:alpha-Globins