Taipoxin, an extremely potent presynaptic snake venom neurotoxin Elucidation of the primary structure of the acidic carbohydrate‐containing taipoxin‐subunit, a prophospholipase homolog

Fohlman, Jan; Lind, Peter; Eaker, David

doi:10.1016/0014-5793(77)80726-6

Cited by 59 publications

(9 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Box 547, Tanunda, South Australia. These venoms were purified by gel filtration chromatography as previously described (Fohlmann et al 1976;Su et al 1983). Naja naja atra PLA 2 was a kind gift from Dr. C.C.…”

Section: Methodsmentioning

confidence: 99%

Presynaptic snake β-neurotoxins produce tetanic fade and endplate potential run-down during neuromuscular blockade in mouse diaphragm

Wilson

Nicholson

1997

Naunyn-Schmiedeberg's Arch Pharmacol

View full text Add to dashboard Cite

The present study investigated the ability of a number of presynaptic snake neurotoxins (snake beta-neurotoxins) to produce nerve-evoked train-of-four fade, tetanic fade and endplate potential run-down during the development of neuromuscular blockade in the isolated mouse phrenic-hemidiaphragm nerve-muscle preparation. All the snake beta-neurotoxins tested, with the exception of notexin, produced train-of-four and tetanic fade of nerve-evoked isometric muscle contractions. Train-of-four fade was not present during the initial depressant or facilitatory phases of muscle tension produced by the snake beta-neurotoxins but developed progressively during the final depressant phase that precedes complete neuromuscular blockade. The 'non-neurotoxic' bovine pancreatic phospholipase A2 and the 'low-toxicity' phospholipase A2 from Naja naja atra venom failed to elicit train-of-four fade, indicating that the phospholipase activity of the snake beta-neurotoxins is not responsible for the development of fade. Intracellular recording of endplate potentials (EPPs) elicited by nerve-evoked trains of stimuli showed a progressive run-down in EPP amplitude during the train following incubation with all snake beta-neurotoxins except notexin. Again this run-down in EPP amplitude was confined to the final depressant phase of snake beta-neurotoxin action. However when EPP amplitude fell to near uniquantal levels (< 3 mV) the extent of toxin induced-fade was reduced. Unlike postjunctional snake alpha-neurotoxins, prejunctional snake beta-neurotoxins interfere with acetylcholine release at the neuromuscular junction during the development of neuromuscular blockade. This study provides further support for the hypothesis that fade in twitch and tetanic muscle tension is due to an underlying rundown in EPP amplitude resulting from a prejunctional alteration of transmitter release rather than a use-dependent block of postjunctional nicotinic receptors.

show abstract

Section: Methodsmentioning

confidence: 99%

Presynaptic snake β-neurotoxins produce tetanic fade and endplate potential run-down during neuromuscular blockade in mouse diaphragm

Wilson

Nicholson

1997

Naunyn-Schmiedeberg's Arch Pharmacol

View full text Add to dashboard Cite

show abstract

“…More recently, an analogous toxin, named cannitoxin, was characterized from the venom of Papuan O. scutellatus [13], although this can be regarded as taipoxin given that the PNG and Australian populations belong to the same species, and indeed, we identified the N-terminal sequence for taipoxin (NLLQFGFMIR), rather than cannitoxin (NLLQFGYMIR), in venom of our PNG O. scutellatus suggesting that both isoforms are likely to exist in this venom. In both populations, the trimers are comprised of subunit α, which is an active neurotoxic PLA 2 , and by subunits β and γ, which are PLA 2 homologues without enzymatic activity [12,13,[32][33][34]. Despite the lack of catalytic and toxic activities of subunits β and γ, they significantly potentiate the toxicity of subunit α [27,35].…”

Section: Venomicsmentioning

confidence: 99%

Comparative proteomic analysis of the venom of the taipan snake, Oxyuranus scutellatus, from Papua New Guinea and Australia: Role of neurotoxic and procoagulant effects in venom toxicity

Herrera

Fernández

Vargas

et al. 2012

Journal of Proteomics

View full text Add to dashboard Cite

“…In contrast to other subunits that have seven disulphide bridges, c subunit has eight disulphide bridges, and the extra disulphide bridge is found in between Cys23 and Cys27. The c subunit is the most important subunit of this complex as it acts as a chaperone to stabilize the complex and protects the a subunit from dissociation [69]. The c subunit most probably interacts with the basic a subunit at the C-terminal region as it contains a stretch of negatively charged residues that are likely to be involved in this interaction [67].…”

Section: Heterotrimeric Pla 2 Complexesmentioning

confidence: 99%

Protein complexes in snake venom

Doley

Kini

2009

Cell. Mol. Life Sci.

201

125

View full text Add to dashboard Cite

Snake venom contains mixture of bioactive proteins and polypeptides. Most of these proteins and polypeptides exist as monomers, but some of them form complexes in the venom. These complexes exhibit much higher levels of pharmacological activity compared to individual components and play an important role in pathophysiological effects during envenomation. They are formed through covalent and/or non-covalent interactions. The subunits of the complexes are either identical (homodimers) or dissimilar (heterodimers; in some cases subunits belong to different families of proteins). The formation of complexes, at times, eliminates the non-specific binding and enhances the binding to the target molecule. On several occasions, it also leads to recognition of new targets as protein-protein interaction in complexes exposes the critical amino acid residues buried in the monomers. Here, we describe the structure and function of various protein complexes of snake venoms and their role in snake venom toxicity.

show abstract

Taipoxin, an extremely potent presynaptic snake venom neurotoxin Elucidation of the primary structure of the acidic carbohydrate‐containing taipoxin‐subunit, a prophospholipase homolog

Cited by 59 publications

References 16 publications

Presynaptic snake β-neurotoxins produce tetanic fade and endplate potential run-down during neuromuscular blockade in mouse diaphragm

Presynaptic snake β-neurotoxins produce tetanic fade and endplate potential run-down during neuromuscular blockade in mouse diaphragm

Comparative proteomic analysis of the venom of the taipan snake, Oxyuranus scutellatus, from Papua New Guinea and Australia: Role of neurotoxic and procoagulant effects in venom toxicity

Protein complexes in snake venom

Contact Info

Product

Resources

About