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A toxin is a poisonous substance produced within living cells or organisms; synthetic toxicants created by artificial processes are thus excluded. The term was first used by organic chemist Ludwig Brieger (1849-1919), derived from the word toxic.
Toxins are often distinguished from other chemical agents by their method of production--the word toxin does not specify method of delivery (compare with venom and the broader meaning of poison--all substances that can also cause disturbances to organisms). It simply means it is a biologically produced poison.
According to an International Committee of the Red Cross review of the Biological Weapons Convention, "Toxins are poisonous products of organisms; unlike biological agents, they are inanimate and not capable of reproducing themselves", and "Since the signing of the Constitution, there have been no disputes among the parties regarding the definition of biological agents or toxins".
Biotoxins vary greatly in purpose and mechanism, and can be highly complex (the venom of the cone snail contains dozens of small proteins, each targeting a specific nerve channel or receptor), or relatively small protein.
Necrotoxins cause necrosis (i.e., death) in the cells they encounter and destroy all types of tissue. Necrotoxins spread through the bloodstream. In humans, skin and muscle tissues are most sensitive to necrotoxins. Organisms that possess necrotoxins include:
Neurotoxins primarily affect the nervous systems of animals. The group neurotoxins generally consists of ion channel toxins that disrupt ion channel conductance. Organisms that possess neurotoxins include:
The term "environmental toxin" can sometimes explicitly include synthetic contaminants such as industrial pollutants and other artificially made toxic substances. As this contradicts most formal definitions of the term "toxin", it is important to confirm what the researcher means when encountering the term outside of microbiological contexts.
Environmental toxins from food chains that may be dangerous to human health include:
The Toxicology and Environmental Health Information Program (TEHIP) at the United States National Library of Medicine (NLM) maintains a comprehensive toxicology and environmental health web site that includes access to toxins-related resources produced by TEHIP and by other government agencies and organizations. This web site includes links to databases, bibliographies, tutorials, and other scientific and consumer-oriented resources. TEHIP also is responsible for the Toxicology Data Network (TOXNET), an integrated system of toxicology and environmental health databases that are available free of charge on the web.
Computational resources for prediction of toxic peptides and proteins
One of the bottlenecks in peptide/protein-based therapy is their toxicity. Recently, in silico models for predicting toxicity of peptides and proteins, developed by Gajendra Pal Singh Raghava's group, predict toxicity with reasonably good accuracy. The prediction models are based on machine learning technique and quantitative matrix using various properties of peptides. The prediction tool is freely accessible to public in the form of web server.
Misuse of the term
When used non-technically, the term "toxin" is often applied to any toxic substance, even though the term toxicant would be more appropriate. Toxic substances not directly of biological origin are also termed poisons and many non-technical and lifestyle journalists follow this usage to refer to toxic substances in general.[clarification needed]
^Vale C, Alfonso A, Vieytes MR, Romarís XM, Arévalo F, Botana AM, Botana LM (March 2008). "In vitro and in vivo evaluation of paralytic shellfish poisoning toxin potency and the influence of the pH of extraction". Anal. Chem. 80 (5): 1770-76. doi:10.1021/ac7022266. PMID18232710.
^Oikawa H, Fujita T, Saito K, Satomi M, Yano Y (2008). "Difference in the level of paralytic shellfish poisoning toxin accumulation between the crabs Telmessus acutidens and Charybdis japonica collected in Onahama, Fukushima Prefecture". Fisheries Science. 73 (2): 395-403. doi:10.1111/j.1444-2906.2007.01347.x.
^Abouabdellah R, Taleb H, Bennouna A, Erler K, Chafik A, Moukrim A (April 2008). "Paralytic shellfish poisoning toxin profile of mussels Perna perna from southern Atlantic coasts of Morocco". Toxicon. 51 (5): 780-86. doi:10.1016/j.toxicon.2007.12.004. PMID18237757.
^Wang L, Liang XF, Zhang WB, Mai KS, Huang Y, Shen D (November 2009). "Amnesic shellfish poisoning toxin stimulates the transcription of CYP1A possibly through AHR and ARNT in the liver of red sea bream Pagrus major". Mar. Pollut. Bull. 58 (11): 1643-48. doi:10.1016/j.marpolbul.2009.07.004. PMID19665739.
^Wang L, Vaquero E, Leão JM, Gogo-Martínez A, Rodríguez Vázquez JA (2001). "Optimization of conditions for the liquid chromatographic-electrospray lonization-mass spectrometric analysis of amnesic shellfish poisoning toxins". Chromatographia. 53 (1): S231-35. doi:10.1007/BF02490333.
^Mouratidou T, Kaniou-Grigoriadou I, Samara C, Kouimtzis T (August 2006). "Detection of the marine toxin okadaic acid in mussels during a diarrhetic shellfish poisoning (DSP) episode in Thermaikos Gulf, Greece, using biological, chemical and immunological methods". Sci. Total Environ. 366 (2-3): 894-904. Bibcode:2006ScTEn.366..894M. doi:10.1016/j.scitotenv.2005.03.002. PMID16815531.
^Doucet E, Ross NN, Quilliam MA (September 2007). "Enzymatic hydrolysis of esterified diarrhetic shellfish poisoning toxins and pectenotoxins". Anal Bioanal Chem. 389 (1): 335-42. doi:10.1007/s00216-007-1489-3. PMID17661021.
^Morohashi A, Satake M, Murata K, Naoki H, Kaspar HF, Yasumoto T (1995). "Brevetoxin B3, a new brevetoxin nalog isolated from the greenshell mussel perna canaliculus involved in neurotoxic shellfish poisoning in new zealand". Tetrahedron Letters. 36 (49): 8995-98. doi:10.1016/0040-4039(95)01969-O.