title: A new polypeptide toxin from the nematocyst venom of an Okinawan sea anemone Phyllodiscus semoni (Japanese name "unbachi-isoginchaku").
abstract: The venomous sea anemone Phyllodiscus semoni causes cases of severe stinging. We isolated Phyllodiscus semoni toxin 20A (PsTX-20A), a hemolytic and lethal polypeptide (20 kDa), from the nematocyst venom of this species for the first time. Furthermore, we sequenced the cDNA encoding PsTX-20A. The deduced amino acid sequence of PsTX-20A showed that this toxin was a new member of the actinoporin family, which consists of several cytolytic polypeptides originating from sea anemones. PsTX-20A showed lethal toxicity to the shrimp Palaemon paucidens when administered via intraperitoneal injection (LD50, 50 microg/kg) and hemolytic activity toward 0.8% sheep red blood cells (ED50, 80 ng/ml).
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: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003064:Cnidarian Venoms / Q000737:chemistry* / Q000235:genetics / Q000633:toxicity*; D007564:Japan; D008969:Molecular Sequence Data; D033541:Palaemonidae / Q000187:drug effects; D010455:Peptides / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification* / Q000633:toxicity*; D012615:Sea Anemones / Q000737:chemistry* / Q000166:cytology* / Q000235:genetics; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
chemical_list: D003064:Cnidarian Venoms; D010455:Peptides