Effects of purified components of jellyfish toxin (Stomolophus meleagris) on active sodium transport

Preliminary results of the in vivo and in vitro characterization of a tentacle venom fraction from the jellyfish Aurelia aurita

The neurotoxic effects produced by a tentacle venom extract and a fraction were analyzed and correlated by in vivo and in vitro approaches. The tentacle venom extract exhibited a wide range of protein components (from 24 to >225 kDa) and produced tetanic reactions, flaccid paralysis, and death when injected into crabs. Two chromatography fractions also produced uncontrolled appendix movements and leg stretching. Further electrophysiological characterization demonstrated that one of these fractions potently inhibited ACh-elicited currents mediated by both vertebrate fetal and adult muscle nicotinic acetylcholine receptors (nAChR) subtypes. Receptor inhibition was concentration-dependent and completely reversible. The calculated IC(50) values were 1.77 μg/μL for fetal and 2.28 μg/μL for adult muscle nAChRs. The bioactive fraction was composed of a major protein component at ~90 kDa and lacked phospholipase A activity. This work represents the first insight into the interaction of jellyfish venom components and muscle nicotinic receptors.

Techniques applicable for purifying Chironex fleckeri (box-jellyfish) venom

A survey of several techniques to isolate a purified lethal factor from the tentacles of Chironex fleckeri was completed. Heterologous band patterns were obtained from specific eluates after gel filtration, ion exchange, immunoaffinity and hydrophobic chromatography. SDS-PAGE revealed a dense band at 24,000 mol. wt in many of these fractions. Isoelectric focusing of the crude venom resulted in considerable loss of activity but indicated significant purification in the fractions having a pI of 5.2-6.8. These fractions were also immunologically active against sera from a convalescing post-evenomation patient. The primary difficulties encountered in jellyfish venom purification are the lack of stability and the tendency of the active toxins to adhere to each other and to various support matrices.

Stabilization of lethal and hemolytic activities of box jellyfish (Chironex fleckeri) venom

The stability of both the lethal and hemolytic activities of box jellyfish (Chironex fleckeri) tentacle extract was assessed after various extraction procedures. Both activities were higher when no buffers or water were used during the initial extraction. Also, when the extract was first filtered through a Sep-pak C18 cartridge, the residual lethal titre, after incubation for 24 hr at room temperature, was increased 16-fold and hemolysis was increased 2.6-fold. Evidence for proteolytic activity in the extract was also obtained and monitored by size exclusion HPLC.