title: Erratum: Purification of a toxic cysteine protease produced by pathogenic Aeromonas hydrophila isolated from rainbow trout.
abstract: An extracellular lethal toxin produced by Aeromonas hydrophila strain RT860715K originally isolated from diseased rainbow trout (Oncorhynchus mykiss) was purified by using Fast Protein Liquid Chromatography system with hydrophobic interaction chromatography and anion exchange columns. The toxin was a cysteine protease, inhibited by L-cysteine, iodoacetic acid, N-ethylamleimide, P-chloromercuibenzene-sulfonic acid and N-α-p-tosyl-1-lysine-chloromethyl ketone (TLCK), and showed maximal activity at pH 6.0. The molecular weight of the purified enzyme proved to be 94 kDa as estimated by SDS-PAGE. In addition, the toxin was also completely inhibited by HgCl2 but partially inhibited by ethylenediamine tetraacetic acid (EDTA) and CuCl2. Both the extracellular products of Aeromonas hydrophila RT860715K and the purified protease were lethal to rainbow trout (weighing 18 g) with LD50 values of 2.87 and 0.93 μg protein g-1 fish body weight, respectively. The addition of L-cysteine completely inhibited the lethal toxicity of the purified protease, indicating that this cysteine protease was a lethal toxin produced by the bacterium.
authors.affiliation: Department of Aquaculture, National Taiwan Ocean University, Keelung, Taiwan.
authors.forename: Ping-Chung
authors.initials: PC
authors.lastname: Liu
authors.forename: Wen-Hsiao
authors.initials: WH
authors.lastname: Chuang
authors.forename: Chih-Ching
authors.initials: CC
authors.lastname: Tu
authors.forename: Kuo-Kau
authors.initials: KK
authors.lastname: Lee
mesh_terms: D016980:Aeromonas hydrophila / Q000201:enzymology* / Q000378:metabolism; D000818:Animals; D001427:Bacterial Toxins / Q000302:isolation & purification* / Q000378:metabolism / Q000633:toxicity; D002847:Chromatography, Agarose / Q000662:veterinary; D002852:Chromatography, Ion Exchange / Q000662:veterinary; D057056:Cysteine Proteases / Q000302:isolation & purification* / Q000378:metabolism / Q000633:toxicity; D004591:Electrophoresis, Polyacrylamide Gel; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005393:Fish Diseases / Q000382:microbiology*; D016905:Gram-Negative Bacterial Infections / Q000382:microbiology / Q000662:veterinary*; D006863:Hydrogen-Ion Concentration; D007928:Lethal Dose 50; D008970:Molecular Weight; D017686:Oncorhynchus mykiss
chemical_list: D001427:Bacterial Toxins; D004791:Enzyme Inhibitors; D057056:Cysteine Proteases