Venom glands

A cloned complementary DNA to a neurotoxin precursor RNA extracted from the venom glands of Laticauda semifasciata was isolated and its nucleotide sequence was identified 11). The cloning of neurotoxin should aid the understanding of structure—function relationship eventually. 

Fig. 1 The structure of a-LTX. (a) Schematic of a-LTX processing in the venom gland, (b) Primary and domain structure. The numbered boxes, ankyrin repeats (ARs). Grey, imperfect repeats C, conserved cysteines residues in the N-terminal domain open arrowhead, insert in the mutant a-LTXN4C. Protein domains identified from the 3D structure (Orlova et al. 2000) are delimited below, (c) 3D reconstructions of the a-LTX monomer, dimer and tetramer, viewed from the top and side. The monomer has been computationally extracted from the experimentally determined tetramer structure. Left-most image, a scheme of the monomer, with the domains designated by different shades of grey. Filled arrowhead, strong association of the head domains in the dimer.

Duan ZG, Yan XJ, He XZ et al (2006) Extraction and protein component analysis of venom from the dissected venom glands of Latrodectus tredecimguttatus. Comp Biochem Physiol B Biochem Mol Biol 145 350-7... 

Silva AM, Liu-Gentry J, Dickey AS et al (2005) a-Latrotoxin increases spontaneous and depolarization-evoked exocytosis from pancreatic islet P-cells. J Physiol 565 783-99 Siu R, Fladd C, Rotin D (2006) N-cadherin is an in vivo substrate for PTPo and partidpates in PTPo-mediated inhibition of axon growth. Mol Cell Biol 27 208-19 Smith DS, Russell FE (1966) Structure of the venom gland of the black widow spider Latrodectus mactans. A preliminary light and electron microscopic study. In Russell FE, Saunders PR (eds) Animal Toxins, Oxford, Pergamon, pp 1-15... 

Cruz-Lopez L., Rojas J. C., De L Cruz-Cordero, R. and Morgan, E. D. (2001b) Behavioral and chemical analysis of venom gland secretion of queens of the ant Solenopsis geminate. J. Chem. Ecol. 27, 2437-2445. 

Sheumack, D. D., Howden, M. E. H., Spence, I. and Quinn, R. J. 1978. Maculotoxin a neurotoxin from the venom glands of the octopus Hapalochlaena maculosa identified as tetrodotoxin. Science 199, 188-189... 

The venom gland is found at the base of the forcipules. Venom passes through the ducts of the forcipules and is injected into the bite site. The components of centipede venom have not been completely identified. Known components include 5-hy-droxytryptamine, histamine, lipids, polysaccharides, and enzymes including proteinases and esterases. Toxin S, which is a cardiotoxic protein, has been isolated from the species Scolopendra subspinipes. Cytolysin is found in the North American giant centipede, Scolopendra heros. 

Approximately 30-40% of snake species produce some type of buccal toxins or venom. The major adaptive functions of venoms and buccal toxins in snakes have been associated with food acquisition, defense, and predigestion of prey items. Venomous species possess specialized structures (venom glands or Duvernoy s glands), which produce venom or toxins and enlarged teeth or fangs, which inject or introduce the venom into the prey item. Venom contains enzymes and proteins that break down cellular structures and interferes with critical functions such... 

The "thorns" are actually long, sharp and poi sonous spines that number in the thousands, growing to a length of 1.5" to 2". A thin layer of skin with venom glands envelopes the... 

The female lancehead gives birth to a litter of up to 8o(8Dio) live young. These hatchlings are about l in length and are bom with fully functioning venom glands. 

JSTX. A group of arylamide toxins from the venom glands of the Japanese joro spider, Nephila clavate, and related species. Blocks glutamate receptors in both Crustacea and mammalia. 

Ornithorhynchus anatinus the duckbill platypus. Males have a venom gland connected to... 

Most people can visualise a fang and realise that it is the fang that delivers the snake s venom to its prey or attacker. Snakes have venom glands which produce and secrete the venom. These glands fall into three types which can be recognised easily when they are cut and prepared for microscopical examination. Their classification is based upon histology and anatomical structure, but conveniently coincides with snake families or genus ... 

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