1JLZ

Solution Structure of a K+-Channel Blocker from the Scorpion Toxin of Tityus cambridgei


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 100 
  • Conformers Submitted: 15 
  • Selection Criteria: structures with the lowest energy 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Solution structure of a K(+)-channel blocker from the scorpion Tityus cambridgei.

Wang, I.Wu, S.H.Chang, H.K.Shieh, R.C.Yu, H.M.Chen, C.

(2002) Protein Sci. 11: 390-400

  • DOI: 10.1110/ps.33402

  • PubMed Abstract: 
  • A new K(+)-channel blocking peptide identified from the scorpion venom of Tityus cambridgei (Tc1) is composed of 23 amino acid residues linked with three disulfide bridges. Tc1 is the shortest known toxin from scorpion venom that recognizes the Shake ...

    A new K(+)-channel blocking peptide identified from the scorpion venom of Tityus cambridgei (Tc1) is composed of 23 amino acid residues linked with three disulfide bridges. Tc1 is the shortest known toxin from scorpion venom that recognizes the Shaker B K(+) channels and the voltage-dependent K(+) channels in the brain. Synthetic Tc1 was produced using solid-phase synthesis, and its activity was found to be the same as that of native Tc1. The pairings of three disulfide bridges in the synthetic Tc1 were identified by NMR experiments. The NMR solution structures of Tc1 were determined by simulated annealing and energy-minimization calculations using the X-PLOR program. The results showed that Tc1 contains an alpha-helix and a 3(10)-helix at N-terminal Gly(4)-Lys(10) and a double-stranded beta-sheet at Gly(13)-Ile(16) and Arg(19)-Tyr(23), with a type I' beta-turn at Asn(17)-Gly(18). Superposition of each structure with the best structure yielded an average root mean square deviation of 0.26 +/- 0.05 A for the backbone atoms and of 1.40 +/- 0.23 A for heavy atoms in residues 2 to 23. The three-dimensional structure of Tc1 was compared with two structurally and functionally related scorpion toxins, charybdotoxin (ChTx) and noxiustoxin (NTx). We concluded that the C-terminal structure is the most important region for the blocking activity of voltage-gated (Kv-type) channels for scorpion K(+)-channel blockers. We also found that some of the residues in the larger scorpion K(+)-channel blockers (31 to 40 amino acids) are not involved in K(+)-channel blocking activity.


    Organizational Affiliation

    Institute of Biomedical Sciences, Academia Sinica, Taipei 115, Taiwan.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Tityustoxin alpha-KTx
A
23Tityus obscurusMutation(s): 0 
Find proteins for P83243 (Tityus obscurus)
Go to UniProtKB:  P83243
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 100 
  • Conformers Submitted: 15 
  • Selection Criteria: structures with the lowest energy 
  • Olderado: 1JLZ Olderado

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2002-02-06
    Type: Initial release
  • Version 1.1: 2008-04-27
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance