1BMR

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


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 60 
  • Conformers Submitted: 25 
  • Selection Criteria: LEAST RESTRAINT VIOLATION 

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This is version 1.2 of the entry. See complete history

Literature

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, J.M.

(1999) J.Mol.Biol. 285: 1749-1763

  • DOI: 10.1006/jmbi.1998.2418

  • PubMed Abstract: 
  • 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 t ...

    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.


    Related Citations: 
    • Sodium Channels as Targets for Neurotoxins. Modes of Action and Interaction of Neurotoxins with Receptor Sites on Sodium Channels
      Gordon, D.
      (1997) Toxins and Signal Transduction (in: Cellular and Molecular Mechanisms of Toxin Action, V.1) --: 119
    • New Toxins Acting on Sodium Channels from the Scorpion Leiurus Quinquestriatus Hebraeus Suggest a Clue to Mammalian Vs Insect Selectivity
      Sautiere, P.,Cestele, S.,Kopeyan, C.,Martinage, A.,Drobecq, H.,Doljansky, Y.,Gordon, D.
      (1998) Toxicon 36: 1141


    Organizational Affiliation

    Laboratoire de RMN Biomoléculaire Associé au CNRS, Université Claude Bernard - Lyon 1 et CPE-Lyon, Villeurbanne, France.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
LQH III ALPHA-LIKE TOXIN
A
68Leiurus quinquestriatus hebraeusN/A
Find proteins for P56678 (Leiurus quinquestriatus hebraeus)
Go to UniProtKB:  P56678
Small Molecules
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
NH2
Query on NH2
A
NON-POLYMERH2 N

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Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 60 
  • Conformers Submitted: 25 
  • Selection Criteria: LEAST RESTRAINT VIOLATION 
  • Olderado: 1BMR Olderado
Software Package:
Software NamePurpose
X-PLORphasing
X-PLORmodel building
X-PLORrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1999-02-16
    Type: Initial release
  • Version 1.1: 2008-03-24
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance