1v91

Solution structure of insectidal toxin delta-paluIT2-NH2

spinqualitylabelsall models 1v91, 20 NMR models Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1v91 is a 1 chain structure with sequence from Paracoelotes luctuosus. Full experimental information is available from OCA. For a guided tour on the structure components use FirstGlance. NonStd Res: NH2 Related: 1v90 Resources: FirstGlance, OCA, RCSB, PDBsum Function [TXDP2_PARLU] Insecticidal toxin. Lethal to lepidopteran larvae. No adverse affects when intracerebroventricularly injected in mice at a dose of 0.2 ug but causes reversible paralysis of legs when injected intracerebroventricularly in mice at a dose of 2.0 ug. Binds to site 4 of insect voltage-gated sodium channel (Nav) and inhibits channel inactivation. 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 PubMed Delta-paluIT1 and delta-paluIT2 are toxins purified from the venom of the spider Paracoelotes luctuosus. Similar in sequence to mu-agatoxins from Agelenopsis aperta, their pharmacological target is the voltage-gated insect sodium channel, of which they alter the inactivation properties in a way similar to alpha-scorpion toxins, but they bind on site 4 in a way similar to beta-scorpion toxins. We determined the solution structure of the two toxins by use of two-dimensional nuclear magnetic resonance (NMR) techniques followed by distance geometry and molecular dynamics. The structures of delta-paluIT1 and delta-paluIT2 belong to the inhibitory cystine knot structural family, i.e. a compact disulfide-bonded core from which four loops emerge. Delta-paluIT1 and delta-paluIT2 contain respectively two- and three-stranded anti-parallel beta-sheets as unique secondary structure. We compare the structure and the electrostatic anisotropy of those peptides to other sodium and calcium channel toxins, analyze the topological juxtaposition of key functional residues, and conclude that the recognition of insect voltage-gated sodium channels by these toxins involves the beta-sheet, in addition to loops I and IV. Besides the position of culprit residues on the molecular surface, difference in dipolar moment orientation is another determinant of receptor binding and biological activity differences. We also demonstrate by electrophysiological experiments on the cloned insect voltage-gated sodium channel, para, heterologuously co-expressed with the tipE subunit in Xenopus laevis oocytes, that delta-paluIT1 and delta-paluIT2 procure an increase of Na+ current. delta-PaluIT1-OH seems to have less effect when the same concentrations are used. Solution structure of two insect-specific spider toxins and their pharmacological interaction with the insect voltage-gated Na+ channel.,Ferrat G, Bosmans F, Tytgat J, Pimentel C, Chagot B, Gilles N, Nakajima T, Darbon H, Corzo G Proteins. 2005 May 1;59(2):368-79. PMID:15726637 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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