Isolation and Characterization of Pelamis platurus (Yellow-bellied Sea Snake) Postsynaptic Isoneurotoxin

Abstract

Pelamis platurus (yellow-bellied sea snake) venom contains several neurotoxins, the major toxin, which is most toxic, and two other isotoxins. The second most toxic neurotoxin (Pelamis toxin b) was isolated and characterized. It contains 60 amino acid residues with only one residue difference from the major toxin, Pelamis toxin a. The difference is at the tenth amino acid residue from the acid terminal. The isoelectric point of toxin b is 8.7. Raman spectroscopic examination of toxin b indicates that the toxin contains a considerable amount of antiparallel beta-structure, beta-turn, and random coil without alpha-helix as the amide I band appears at 1673 cm-1 and the amide III band at 1246 cm-1. Circular dichroic studies also indicate a typical beta-sheet structure. The Pelamis toxin b is a typical postsynaptic neurotoxin as it binds to the acetylcholine receptor competitively with a well known toxin, alpha-bungarotoxin. The LD50 of toxin b is 0.185 microgram g-1 in mice by intravenous injection, indicating high toxicity of a postsynaptic neurotoxin.

Two color morphs of the pelagic yellow-bellied sea snake, Pelamis platura, from different locations of Costa Rica: Snake venomics, toxicity, and neutralization by antivenom

“…The existence of an isoform named "pelamitoxin b" was reported later [56], differing from the former by a single amino acid at the tenth residue (Q/E), and this might explain the close elution and undistingushable isotope-averaged molecular mass observed for the overlapping peaks 1-2 ( Fig.3), which were pooled for further functional and immunochemical analyses.…”

Isolation and Chemical Characterization of a Toxin Isolated from the Venom of the Sea Snake, Hydrophis torquatus aagardi

“…The LD 50 of purified sea snake neurotoxin from Pelamis platurus by i.v. was 0.13 mg/g [4]. A purified toxin from Hydrophis ornatus gave an LD 50 value of 0.09 mg/g by intramuscular injection [16].…”

“…Sea snake venom is a mixture of proteins with diverse biological activities [1,2]. In our laboratory, we have isolated and characterized neurotoxins from many species of Hydrophiinae sea snakes [3,4,5,6]. In this report, we present data on the isolation of a toxin from the venom of Hydrophis torquatus aagardi belonging to the Hydrophiinae subfamily.…”

Snakebites in Colombia

“…So the incidence of dry bites (non-envenoming or only trivial envenoming) is high (80 %) (Reid 1975). Its bite is usually painless, without local swelling, although its venom is myotoxic (rhabdomyolytic), causing muscle pains; besides, it is nephrotoxic and postsynaptically neurotoxic (Tu and Fulde 1987;Mori et al 1989;Otero 2007).…”

“…and Pelamis platurus venoms is the postsynaptic blockade by competitive inhibition of acetylcholine (a-neurotoxins). This group of toxins belongs to the three-finger toxin superfamily (3FTx) (Otero 2007(Otero , 2014Rey-Suárez et al 2012;Da Silva and Bucaretchi 2003;Brazil 1987;Mori et al 1989). The venom of M. dissoleucus from Colombia also has postsynaptic action combined with myotoxic effect (Renjifo et al 2012), the latter being similar to that previously described for M. mipartitus venom from Colombia (Otero et al 1992b).…”