1axh
From Proteopedia
ATRACOTOXIN-HVI FROM HADRONYCHE VERSUTA (AUSTRALIAN FUNNEL-WEB SPIDER, NMR, 20 STRUCTURES
Structural highlights
Function[TOT1A_HADVE] Reversibly and voltage-independently blocks both mid-low- (M-LVA) and high-voltage-activated (HVA) calcium channels in cockroach DUM neurons. Lethal to many insect orders but not toxic to mice or rabbits. May target the insect high-voltage-activated calcium channel Dmca1D. Also inhibits acarines calcium channels. An extremely high toxin concentration partially inhibits Cav1.2/CACNA1C, Cav2.1/CACNA1A and Cav2.2/CACNA1B calcium channel of rats. As for omega-AcTx-Hv2a, the phenotypic effect of injection of this toxin into lone star ticks (Amblyomma americanum) is curling of all eight legs into closed loops.[1] [2] [3] [4] [5] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedA family of potent insecticidal toxins has recently been isolated from the venom of Australian funnel web spiders. Among these is the 37-residue peptide omega-atracotoxin-HV1 (omega-ACTX-HV1) from Hadronyche versuta. We have chemically synthesized and folded omega-ACTX-HV1, shown that it is neurotoxic, ascertained its disulphide bonding pattern, and determined its three-dimensional solution structure using NMR spectroscopy. The structure consists of a solvent-accessible beta-hairpin protruding from a disulphide-bonded globular core comprising four beta-turns. The three intramolecular disulphide bonds from a cystine knot motif similar to that seen in several other neurotoxic peptides. Despite limited sequence identity, omega-ACTX-HV1 displays significant structural homology with the omega-agatoxins and omega-conotoxins, both of which are vertebrate calcium channel antagonists; however, in contrast with these toxins, we show that omega-ACTX-HV1 inhibits insect, but not mammalian, voltage-gated calcium channel currents. The structure of a novel insecticidal neurotoxin, omega-atracotoxin-HV1, from the venom of an Australian funnel web spider.,Fletcher JI, Smith R, O'Donoghue SI, Nilges M, Connor M, Howden ME, Christie MJ, King GF Nat Struct Biol. 1997 Jul;4(7):559-66. PMID:9228949[6] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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