title: Novel proteinaceous toxins from the nematocyst venom of the Okinawan sea anemone Phyllodiscus semoni Kwietniewski.
abstract: The Okinawan sea anemone Phyllodiscus semoni is known to cause cases of severe stinging. We isolated P. semoni toxins 60A and 60B (PsTX-60A and PsTX-60B; ca. 60 kDa) as the major toxins from the isolated nematocysts of this species for the first time. PsTX-60A and PsTX-60B showed lethal toxicity to the shrimp Palaemon paucidence when administered via intraperitoneal injection (LD(50) values: 800-900 and 800 microg/kg, respectively) and hemolytic activity toward a 0.8% suspension of sheep red blood cells (ED(50) values: 600 and 300 ng/ml, respectively). Furthermore, we sequenced the cDNA encoding PsTX-60A. The deduced amino acid sequence of PsTX-60A did not show any similarity to previously reported proteins. The N-terminal amino acid sequence of PsTX-60B showed homology with that of PsTX-60A. These toxins represent a novel class of cytolytic proteinaceous toxins.
authors.affiliation: Suntory Institute for Bioorganic Research, 1-1-1 Wakayamadai, Shimamoto, Mishima, Osaka 618-8503, Japan. nagai@tokyo-u-fish.ac.jp
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nagai
authors.forename: Naomasa
authors.initials: N
authors.lastname: Oshiro
authors.forename: Kyoko
authors.initials: K
authors.lastname: Takuwa-Kuroda
authors.forename: Setsuko
authors.initials: S
authors.lastname: Iwanaga
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Nozaki
authors.forename: Terumi
authors.initials: T
authors.lastname: Nakajima
mesh_terms: D000465:Algorithms; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000378:metabolism; D033364:Decapoda; D004912:Erythrocytes / Q000187:drug effects; D008387:Marine Toxins / Q000737:chemistry* / Q000302:isolation & purification* / Q000633:toxicity; D008969:Molecular Sequence Data; D014176:Protein Biosynthesis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012615:Sea Anemones; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D012756:Sheep
chemical_list: D018076:DNA, Complementary; D008387:Marine Toxins; C463479:TX-60A protein, Phyllodiscus semoni