title: Purification and characterization of gigantoxin-4, a new actinoporin from the sea anemone Stichodactyla gigantea.
abstract: A new Cytolysin, termed as Gigantoxin-4, was isolated from the sea anemone Stichodactyla gigantea and found to be highly homologous with Cytolysin-3 (HMg III) from Heteractis magnifica, RTX-A from Radianthus macrodactylus, and Sticholysin-1 (St I) and Sticholysin-2 (St II) from Stichodactyla helianthus (homology 82%, 86%, 82% and 86% respectively). Its 20 N-terminal residues were identified and the full-length cDNA sequence was obtained by reverse transcription-polymerase chain reaction (RT-PCR). Multiple sequence alignments with other Cytolysins of the actinoporin family clearly indicated that Gigantoxin-4 belongs to this protein family. SDS-PAGE electrophoresis showed that this new actinoporin had a molecular mass of about 19 kDa, and possessed a high hemolytic activity to human erythrocytes (HA(50)= 40 ng/ml), which was inhibited by pre-incubation with sphingomyelin (SM) or SM-cholesterol mixtures. Our in vivo experiments showed that Gigantoxin-4 had wide toxicity to the rat cardiovascular system and the respiratory system. A concentration of 30 μg/kg Gigantoxin-4, i.v. produced a positive inotropic effect on the rat heart although final cardiovascular failure was inevitable, and 60 μg/kg Gigantoxin-4 caused respiratory arrest rapidly resulting in rat death. HE staining indicated pathological changes in various organs and tissues after i.v. administration of Gigantoxin-4.
authors.affiliation: Department of Biochemistry and Molecular Biology, Second Military Medical University, Shanghai, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Hu
authors.forename: Wei
authors.initials: W
authors.lastname: Guo
authors.forename: Liang-Hua
authors.initials: LH
authors.lastname: Wang
authors.forename: Jian-Guang
authors.initials: JG
authors.lastname: Wang
authors.forename: Xiao-Yu
authors.initials: XY
authors.lastname: Liu
authors.forename: Bing-Hua
authors.initials: BH
authors.lastname: Jiao
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D003064:Cnidarian Venoms / Q000737:chemistry / Q000302:isolation & purification / Q000633:toxicity*; D003603:Cytotoxins / Q000737:chemistry / Q000302:isolation & purification*; D006321:Heart / Q000187:drug effects; D006461:Hemolysis / Q000187:drug effects; D006801:Humans; D008099:Liver / Q000187:drug effects / Q000201:enzymology; D008297:Male; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D051381:Rats; D017207:Rats, Sprague-Dawley; D012615:Sea Anemones / Q000737:chemistry* / Q000235:genetics; D016415:Sequence Alignment; D053835:Unilamellar Liposomes; D016277:Ventricular Function, Left / Q000187:drug effects
chemical_list: D003064:Cnidarian Venoms; D003603:Cytotoxins; D053835:Unilamellar Liposomes; C562084:gigantoxin-4, Stichodactyla gigantea