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Venom
The venoms of scorpions contain several neurotoxins that consist of low-molecular weight basic proteins, mucus, salts, and a variety of organic compounds (Simard & Watt 1990). The neurotoxins are interesting in that they typically exhibit preferential toxicity to specific animals (e.g., toxins specific to insects and mammals). Relatively few of the scorpion venoms that have been studied exhibit enzymatic activity. Although scorpion venoms are best known for the harm they cause, recent research demonstrates that they have properties that may make them medically useful. Venoms of some species (e.g., Hadrurus aztecus, Pandinus imperator) have anti-microbial properties that might eventually lead to the development of new antibiotics (Torres-Larrios, et al. 2000; Corzo, et. al. 2001). Kaliotoxin, a component of Androctonus mauretanicus mauretanicus venom, has been shown to reduce bone loss in laboratory rats suffering from periodontal disease (Valverde, et al. 2004). Chlorotoxin, isolated from the scorpion Leiurus quinquestriatus, selectively binds to glioma (brain tumor) cells; linked with anticancer drugs, this toxin (actually, its genetically engineered version) can serve as a marker for diagnosis and therapy (Soroceanu, et al. 1998). More recently, it has been shown that chlorotoxin prevents glioma cells from spreading into normal brain tissue (DeShane, et al. 2003). A relatively new angle of applied research has been to utilize the insect-specific neurotoxins of scorpion venoms to generate recombinant viral pesticides to help control agricultural pests (Loret & Hammock 2001). Although the research thus far has been focused on buthid scorpions, there is reason to expect that other species may yield potent insect toxins for pesticide development.
Literature Cited: DeShane, J., C. C. Garner, & H. Sontheimer. 2003. Chlorotoxin inhibits glioma cell invasion via matrix metalloproteinase-2. Journal of Biological Chemistry, 278: 4135-4144. Loret, E. and B. Hammock. 2001. Structure and neurotoxicity of venoms. In: Brownell, P. and G. Polis (Eds.). Scorpion Biology and Research. Oxford University Press, New York, 204-233. Torres-Larios, A., G. B. Gurrola, F. Z. Zamudio & L. D. Possani. 2000. Hadrurin, a new antimicrobial peptide from the venom of the scorpion Hadrurus aztecus. European Journal of Biochemistry, 267: 5023-5031 (2000). Soroceanu, L.., Y. Gillespie, M. B. Khazaeli, & H. Sontheimer. Use of chlorotoxin for targeting of primary brain tumors. Cancer Research, 58: 4871-4879. Valverde, P., T.
Kawai, & M. A. Taubman. 2004. Selective Blockade of Voltage-Gated
Potassium Channels Reduces Inflammatory Bone Resorption in
Experimental Periodontal Disease. Journal of Bone and Mineral
Research, 19: 155-164. |
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