1C49

STRUCTURAL AND FUNCTIONAL DIFFERENCES OF TWO TOXINS FROM THE SCORPION PANDINUS IMPERATOR


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 500 
  • Conformers Submitted: 18 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Structural and functional differences of two toxins from the scorpion Pandinus imperator.

Klenk, K.C.Tenenholz, T.C.Matteson, D.R.Rogowski, R.S.Blaustein, M.P.Weber, D.J.

(2000) Proteins 38: 441-449


  • PubMed Abstract: 
  • The Pandinotoxins, PiTX-K alpha and PiTX-K beta, are members of the Charybdotoxin family of scorpion toxins that can be used to characterize K+ channels. PiTX-K alpha differs from PiTX-K beta, another peptide from Pandinus imperator, by one residue ( ...

    The Pandinotoxins, PiTX-K alpha and PiTX-K beta, are members of the Charybdotoxin family of scorpion toxins that can be used to characterize K+ channels. PiTX-K alpha differs from PiTX-K beta, another peptide from Pandinus imperator, by one residue (P10E). When the two toxins are compared in a physiological assay, the affinity of PiTX-K beta for voltage-gated, rapidly inactivating K+ channels in dorsal root ganglia (DRG) neurons is 800-fold lower than that of PiTX-K alpha (K alpha-IC50 = 8.0 nM versus K beta-IC50 = 6,500 nM). To understand this difference, the three-dimensional structure of PiTX-K beta was determined by nuclear magnetic resonance (NMR) spectroscopy and compared to that of PiTX-K alpha. This comparison shows that structural differences between the two toxins occur at a residue that is critical for blocking K+ channels (K27) as well as at the site of the natural mutation (P10E). In PiTX-K beta, the negatively charged carboxylate oxygen of E10 can approach the positive charge of K27 and presumably reduces the net positive charge in this region of the toxin. This is likely the reason why PiTX-K beta binds K+ channels from DRG neurons with a much lower affinity than does PiTX-K alpha.


    Related Citations: 
    • Three New Toxins from the Scorpion Pandinus Imperator Selectively Block Certain Voltage-Gated K+ Channels
      Rogowski, R.S.,Collins, J.H.,O'Neill, T.J.,Gustafson, T.A.,Werkman, T.R.,Rogawski, M.A.,Tenenholz, T.C.,Weber, D.J.,Blaustein, M.P.
      (1996) Mol.Pharmacol. 50: 1167


    Organizational Affiliation

    Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
TOXIN K-BETA
A
35Pandinus imperatorN/A
Find proteins for P55928 (Pandinus imperator)
Go to UniProtKB:  P55928
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 500 
  • Conformers Submitted: 18 
  • Olderado: 1C49 Olderado

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2000-03-22
    Type: Initial release
  • Version 1.1: 2008-04-26
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance