Venom peptides

Bacterial botulinum toxin blocks presynaptic acetylcholine release 725 Snake, scorpion, spider, fish and snail peptide venoms act on multiple molecular targets at the neuromuscular junction 727 Electrolyte imbalances alter the voltage sensitivity of muscle ion channels 728... 

Acetylcholine receptors - muscarinic agonists There are a number of natural plant alkaloid toxins, including arecoline, muscarine and pilocarpine and green mamba snake peptides venoms, including MTl, MT2, MTS and MT4. 

Numerous chemical classes of calmodulin antagonists have been reported, and include (nonexclu-sively) the phenothiazine and diphenylbutylpiper-idine antipsychotics, tricyclic and nontricyclic antidepressants, certain peptide venoms (mastosparan. 

HISTAMINE RELEASE BY DRUGS, PEPTIDES, VENOMS, AND OTHER AGENTS... 

Recently, a variety of natural peptides that form transmembrane channels have been identified and characterized. Melittin (Figure 10.35) is a bee venom toxin peptide of 26 residues. The cecropins are peptides induced in Hyalophora cecropia (Figure 10.36) and other related silkworms when challenged by bacterial infections. These peptides are thought to form m-helical aggregates in mem-... 

Conotoxins are the venoms of the marine cone snails. The >500 Conus species produce >10,000 different toxins. All are cysteine-rich peptides of 10-30 amino... 

Sarafotoxin is a 21-amino acid peptide which has some structural similarity with endothelins and was isolated from the venom of the burrowing asp. Sarafotoxin is a selective agonist of the endothelin ETB-receptor. 

Hymenoptera venoms are composed of biogenic amines and other low molecular weight substances, of basic peptides and of proteins. Injection of venom by Hymenoptera stings has toxic effects, due to biogenic amines, peptides and proteins biogenic amines such as histamine cause pain, are vasodilatory and increase... 

Bumble bee venom contains also a phospholipase A2 with partial identity to bee venom phospholipase Aj and a protease, but no melittin. Instead there are several small peptides called bombolitins [9]. There is limited cross-reactivity between honey bee and bumblebee venoms [2]. 

These include nicotinic acetylcholine receptors, neuronal calcium channels, muscle sodium channels, vasopressin receptors, and iV-methyl-D-aspartate (NMDA) receptors. Some general features of the structure, function, and evolution of biologically active peptides isolated from Conus venom are presented. 

OLIVERA ET AL. Conotojdns Targeted Peptide Ligands from Snail Venoms 257... 

OLIVERAETAL. Conotoxins Targeted Peptide Ligands from Smil Venoms 259... 

When a cone snail envenomates its prey, the latter is invariably paralyzed. In all cases, the paralytic toxins in the venom ("conotoxins") appear to be small peptides, most commonly with 3 disulfide bonds (although conotoxins with 2 or 4 S-S bonds... 

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