A Novel Protein Toxin from the Deadly Box Jellyfish (Sea Wasp, Habu-kurage)Chiropsalmus quadrigatus

Abstract

The deadly box jellyˆsh (Sea Wasp, Habu-kurage in Japanese)Chiropsalmus quadrigatus Haeckel (Cubozoa) is distributed widely in the tropical Paciˆc region. In Japan, three fatal cases due to stings from this species have been reported o‹cially. We successfully isolated C. quadrigatus toxin-A (CqTX-A, 44 kDa), a major proteinaceous toxin, for theˆrst time, from the nematocysts of C. quadrigatus. CqTX-A showed lethal toxicity to crayˆsh when administered via intraperitoneal injection (LD 50 ＝80 mg W kg) and hemolytic activity toward 0.8% sheep red blood cells (ED 50 ＝ 160 ng W 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 jellyˆsh toxins.

Evolution of box jellyfish (Cnidaria: Cubozoa), a group of highly toxic invertebrates

“…In contrast to the notion that chirodropids represent the most lethal box jellyfishes, haemolytic activity of purified toxin proteins appears lower in C. yamaguchii (Nagai et al 2002; as C. quadrigatus) than in Alatina sp. (Nagai et al 2000a; as Carybdea alata) and highest in Carybdea brevipedalia (Nagai et al 2000b;as C. rastoni [sic]).…”

Chironex fleckeri (Box Jellyfish) Venom Proteins

“…Variability in hemolytic activity is also apparent when comparing toxin family members of other box jellyfish. In studies of A. moseri, C. rastonii, and C. yamaguchii, HU 50 values for purified CaTX-A and CrTX-A (Type II toxins) were at least 10-fold lower than purified CqTX-A (Type I toxin) (5,7,8). However, as mentioned previously, hemolysis has never been reported as a clinical feature of human envenoming, which suggests that the cubozoan toxins preferentially target other cell types in vivo.…”

Recent Progress in Jellyfish Toxin Study

“…CqTX-A, CrTX-A, and CaTX-A caused 50% hemolysis in 0.8% sheep red blood cells at a concentration of 160 ng/ ml, 2 ng/ml, and 70 ng/ml, respectively (Table 1). 5,6,8) These data indicate that CqTX-A is less toxic than CrTX-A and CaTX-A. The number of tentacles of C. quadrigatus is several times greater than that of C. alata or C. rastoni.…”

“…8) Comparison of the box jellyfish toxin amino acid sequences with those of other proteins using the BLAST (basic local alignment search tool) algorithm showed no significant similarity. 8) Since a novel bioactive protein family has emerged from these studies of the box jellyfish toxins (CrTXs, CaTX-A, and CqTX-A), we propose here to designate these novel bioactive proteins as the box jellyfish toxin family. Secondary structural analysis of these toxins predicted the presence of α-helices that existed in the N-terminus region.…”