| 词条 | Scorpion toxin |
| 释义 |
| Symbol = Toxin_3 | Name = Scorpion long-chain toxin | image =scorpiontoxinproteinimage.png | width = | caption = Crystal structure of toxin II from the scorpion Androctonus australis Hector.[1] | Pfam= PF00537 | InterPro= IPR002061 | SMART= | Prosite = | SCOP = 2sn3 | TCDB = 8.B.1 | OPM family= 58 | OPM protein= 1djt | PDB= }}{{Infobox protein family | Symbol = Toxin_2 | Name = Scorpion short toxin | image = 1agt.png | width = | caption = Agitoxin-2. Disulphide bonds are highlighted. PDB {{PDBe|1agt}} [2] | Pfam = PF00451 | Pfam_clan = CL0054 | InterPro = IPR001947 | SMART = | PROSITE = PDOC00875 | MEROPS = | SCOP = | TCDB = 8.B.2 | OPM family = 58 | OPM protein = 1ne5 | CAZy = | CDD = }} Scorpion toxins are proteins found in the venom of scorpions. Their toxic effect may be mammal- or insect-specific and acts by binding to sodium channels, inhibiting the inactivation of activated channels and blocking neuronal transmission. The family includes related short- and long-chain scorpion toxins. It also contains a group of proteinase inhibitors from the plants Arabidopsis thaliana and Brassica spp. The Brassica napus (Oil seed rape) and Sinapis alba (White mustard) inhibitors,[3][4] inhibit the catalytic activity of bovine beta-trypsin and bovine alpha-chymotrypsin, which belong to MEROPS peptidase family S1 ({{InterPro|IPR001254}}).[5] This group of proteins is now used in the creation of insecticides, vaccines, and protein engineering scaffolds. StructureThe complete covalent structure of several such toxins has been deduced: They comprise around 66 amino acid residues forming a three stranded anti-parallel beta sheet over which lies an alpha helix of approximately three turns. Four disulfide bridges cross-link the structure of the long-chain toxins whereas the short toxins contain only three.[6][7] BmKAEP, an anti-epilepsy peptide isolated from the venom of the Manchurian scorpion,[8] shows similarity to both scorpion neurotoxins and anti-insect toxins. FunctionThe toxin's molecular function is to inhibit ion channels. Scorpion toxins are used in insecticides, vaccines, and protein engineering scaffolds. The toxins are now used to treat cancer patients by injecting fluorescent scorpion toxin into cancerous tissue to show tumor boundaries. Scorpion toxin genes are also used to kill insect pests by creating hypervirulent fungus in the insect through gene insertion. Subfamilies
References1. ^{{PDB|1PTX}}; {{cite journal | vauthors = Housset D, Habersetzer-Rochat C, Astier JP, Fontecilla-Camps JC | title = Crystal structure of toxin II from the scorpion Androctonus australis Hector refined at 1.3 A resolution | journal = Journal of Molecular Biology | volume = 238 | issue = 1 | pages = 88–103 | date = April 1994 | pmid = 8145259 | doi = 10.1006/jmbi.1994.1270 }} 2. ^{{cite journal | vauthors = Krezel AM, Kasibhatla C, Hidalgo P, MacKinnon R, Wagner G | title = Solution structure of the potassium channel inhibitor agitoxin 2: caliper for probing channel geometry | journal = Protein Science | volume = 4 | issue = 8 | pages = 1478–89 | date = August 1995 | pmid = 8520473 | pmc = 2143198 | doi = 10.1002/pro.5560040805 }} 3. ^{{cite journal | vauthors = Ceciliani F, Bortolotti F, Menegatti E, Ronchi S, Ascenzi P, Palmieri S | title = Purification, inhibitory properties, amino acid sequence and identification of the reactive site of a new serine proteinase inhibitor from oil-rape (Brassica napus) seed | journal = FEBS Letters | volume = 342 | issue = 2 | pages = 221–4 | date = April 1994 | pmid = 8143882 | doi = 10.1016/0014-5793(94)80505-9 }} 4. ^{{cite journal | vauthors = Menegatti E, Tedeschi G, Ronchi S, Bortolotti F, Ascenzi P, Thomas RM, Bolognesi M, Palmieri S | title = Purification, inhibitory properties and amino acid sequence of a new serine proteinase inhibitor from white mustard (Sinapis alba L.) seed | journal = FEBS Letters | volume = 301 | issue = 1 | pages = 10–4 | date = April 1992 | pmid = 1451776 | doi = 10.1016/0014-5793(92)80199-Q }} 5. ^{{cite journal | vauthors = Rawlings ND, Tolle DP, Barrett AJ | title = Evolutionary families of peptidase inhibitors | journal = The Biochemical Journal | volume = 378 | issue = Pt 3 | pages = 705–16 | date = March 2004 | pmid = 14705960 | pmc = 1224039 | doi = 10.1042/BJ20031825 }} 6. ^{{cite journal | vauthors = Kopeyan C, Mansuelle P, Sampieri F, Brando T, Bahraoui EM, Rochat H, Granier C | title = Primary structure of scorpion anti-insect toxins isolated from the venom of Leiurus quinquestriatus quinquestriatus | journal = FEBS Letters | volume = 261 | issue = 2 | pages = 423–6 | date = February 1990 | pmid = 2311768 | doi = 10.1016/0014-5793(90)80607-K }} 7. ^{{cite journal | vauthors = Gregoire J, Rochat H | title = Covalent structure of toxins I and II from the scorpion Buthus occitanus tunetanus | journal = Toxicon | volume = 21 | issue = 1 | pages = 153–62 | year = 1983 | pmid = 6845379 | doi = 10.1016/0041-0101(83)90058-2 }} 8. ^{{cite journal | vauthors = Zhou XH, Yang D, Zhang JH, Liu CM, Lei KJ | title = Purification and N-terminal partial sequence of anti-epilepsy peptide from venom of the scorpion Buthus martensii Karsch | journal = The Biochemical Journal | volume = 257 | issue = 2 | pages = 509–17 | date = January 1989 | pmid = 2930463 | pmc = 1135608 | doi = 10.1042/bj2570509 }} External links
3 : Protein toxins|Peripheral membrane proteins|Invertebrate toxins |
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