title: A novel protein toxin from the deadly box jellyfish (Sea Wasp, Habu-kurage) Chiropsalmus quadrigatus.
abstract: The deadly box jellyfish (Sea Wasp, Habu-kurage in Japanese) Chiropsalmus quadrigatus Haeckel (Cubozoa) is distributed widely in the tropical Pacific region. In Japan, three fatal cases due to stings from this species have been reported officially. We successfully isolated C. quadrigatus toxin-A (CqTX-A, 44 kDa), a major proteinaceous toxin, for the first time, from the nematocysts of C. quadrigatus. CqTX-A showed lethal toxicity to crayfish when administered via intraperitoneal injection (LD50 = 80 microg/kg) and hemolytic activity toward 0.8% sheep red blood cells (ED50 = 160 ng/ml). Furthermore, we sequenced the cDNA encoding CqTX-A. The deduced amino acid sequence of CqTX-A (462 amino acids) showed 25.2% and 21.6% sequence similarity to Carybdea rastoni toxins (CrTXs) and Carybdea alata toxin-A (CrTX-A), respectively, which are Cubozoan jellyfish toxins.
authors.affiliation: Suntory Institute for Bioorganic Research, Mishima, Osaka, Japan. nagai@tokyo-u-fish.ac.jp
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nagai
authors.forename: Kyoko
authors.initials: K
authors.lastname: Takuwa-Kuroda
authors.forename: Masahiro
authors.initials: M
authors.lastname: Nakao
authors.forename: Naomasa
authors.initials: N
authors.lastname: Oshiro
authors.forename: Setsuko
authors.initials: S
authors.lastname: Iwanaga
authors.forename: Terumi
authors.initials: T
authors.lastname: Nakajima
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D003400:Astacoidea; D001483:Base Sequence; D003064:Cnidarian Venoms / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification / Q000633:toxicity; D018076:DNA, Complementary; D004912:Erythrocytes / Q000187:drug effects; D006461:Hemolysis; D008969:Molecular Sequence Data; D010449:Peptide Mapping; D017433:Protein Structure, Secondary; D011506:Proteins / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification / Q000633:toxicity; D037401:Scyphozoa; D020539:Sequence Analysis, Protein; D017386:Sequence Homology, Amino Acid; D012756:Sheep
chemical_list: C465975:Chiropsalmus quadrigatus toxin-A; D003064:Cnidarian Venoms; D018076:DNA, Complementary; D011506:Proteins