Novel proteinaceous toxins from the nematocyst venom of the Okinawan sea anemone Phyllodiscus semoni Kwietniewski

• Published in: Biochemical and biophysical research communications 2002-06, Vol.294 (4), p.760-763
• Main Authors: Nagai, Hiroshi, Oshiro, Naomasa, Takuwa-Kuroda, Kyoko, Iwanaga, Setsuko, Nozaki, Masatoshi, Nakajima, Terumi
• Format: Article
• Language: English
• Subjects: Algorithms; Amino Acid Sequence; Animals; Base Sequence; Cloning, Molecular; Decapoda (Crustacea); DNA, Complementary - metabolism; Erythrocytes - drug effects; Hemolysis; Marine; Marine Toxins - chemistry; Marine Toxins - isolation & purification; Marine Toxins - toxicity; Molecular Sequence Data; Nematocyst; Phyllodiscus semoni; Protein; Protein Biosynthesis; PsTX; Reverse Transcriptase Polymerase Chain Reaction; Sea anemone; Sea Anemones; Sequence Analysis, DNA; Sequence Homology, Amino Acid; Sheep; Toxin
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/S0006-291X(02)00547-8

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 μg/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.