1bmr

ALPHA-LIKE TOXIN LQH III FROM SCORPION LEIURUS QUINQUESTRIATUS HEBRAEUS, NMR, 25 STRUCTURES

spinqualitylabelsall models 1bmr, 25 NMR models Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1bmr is a 1 chain structure with sequence from Leiurus quinquestriatus hebraeus. Full experimental information is available from OCA. For a guided tour on the structure components use FirstGlance. NonStd Res: NH2 Resources: FirstGlance, OCA, RCSB, PDBsum 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 NMR structures of a new toxin from the scorpion Leiurus quinquestriatus hebraeus (Lqh III) have been investigated in conjunction with its pharmacological properties. This toxin is proposed to belong to a new group of scorpion toxins, the alpha-like toxins that target voltage-gated sodium channels with specific properties compared with the classical alpha-scorpion toxins. Electrophysiological analysis showed that Lqh III inhibits a sodium current inactivation in the cockroach axon, but induces in addition a resting depolarization due to a slowly decaying tail current atypical to other alpha-toxin action. Binding studies indicated that radiolabeled Lqh III binds with a high degree of affinity (Ki=2.2 nM) on cockroach sodium channels and that the alpha-toxin from L quinquestriatus hebraeus highly active on insects (LqhalphaIT) and alpha-like toxins compete at low concentration for its receptor binding site, suggesting that the alpha-like toxin receptor site is partially overlapping with the receptor site 3. Conversely, in rat brain, Lqh III competes for binding of the most potent anti-mammal alpha-toxin from Androctonus australis Hector venom (AaH II) only at very high concentration. The NMR structures were used for the scrutiny of the similarities and differences with representative scorpion alpha-toxins targeting the voltage-gated sodium channels of either mammals or insects. Three turn regions involved in the functional binding site of the anti-insect LqhalphaIT toxin reveal significant differences in the Lqh III structure. The electrostatic charge distribution in the Lqh III toxin is also surprisingly different when compared with the anti-mammal alpha-toxin AaH II. Similarities in the electrostatic charge distribution are, however, recognized between alpha-toxins highly active on insects and the alpha-like toxin Lqh III. This affords additional important elements to the definition of the new alpha-like group of scorpion toxins and the mammal versus insect scorpion toxin selectivities. NMR structures and activity of a novel alpha-like toxin from the scorpion Leiurus quinquestriatus hebraeus.,Krimm I, Gilles N, Sautiere P, Stankiewicz M, Pelhate M, Gordon D, Lancelin JM J Mol Biol. 1999 Jan 29;285(4):1749-63. PMID:9917409 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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