title: Purification and characterization of a proteinaceous toxin from the Serum of Japanese eel Anguilla japonica.
abstract: Although eels are well known to contain toxins in the serum, their chemical properties have remained to be clarified for a long time. In this study, a proteinaceous toxin was purified from the serum of Japanese eel Anguilla japonica by anion-exchange HPLC, hydroxyapatite HPLC and gel filtration HPLC. The toxin was lethal to both mice and crabs; the LD(50) of the purified toxin against mice (intravenous injection) and crabs (injection into body cavity) were estimated to be 670 and 450 mug kg(-1), respectively. Chemical analysis data revealed that the toxin is a monomeric simple protein with a molecular mass of 100 kDa and an isoelectric point of 6.1. Three of the peptide fragments produced by digestion of the purified toxin with lysylendopeptidase were sequenced. However, a database search based on the determined partial amino acid sequence failed to find any proteins sharing homology with the A. japonica serum toxin.
authors.affiliation: Department of Food Science and Technology, Tokyo University of Marine Science and Technology, Konan-4, Minato-ku, Tokyo 108-8477, Japan.
authors.forename: Mireiyu
authors.initials: M
authors.lastname: Yoshida
authors.forename: Seiji
authors.initials: S
authors.lastname: Sone
authors.forename: Kazuo
authors.initials: K
authors.lastname: Shiomi
mesh_terms: D000595:Amino Acid Sequence; D000811:Anguilla / Q000097:blood*; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D003445:Crustacea / Q000187:drug effects; D007928:Lethal Dose 50; D008297:Male; D008387:Marine Toxins / Q000097:blood / Q000302:isolation & purification* / Q000633:toxicity; D051379:Mice; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000097:blood / Q000302:isolation & purification* / Q000633:toxicity
chemical_list: D008387:Marine Toxins; D010446:Peptide Fragments