2MEN

NMR solution structure of the GS-TAMAPIN MUTATION R13A


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 200 
  • Conformers Submitted: 20 
  • Selection Criteria: structures with the least restraint violations 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Cytotoxicity of recombinant tamapin and related toxin-like peptides on model cell lines.

Ramirez-Cordero, B.Toledano, Y.Cano-Sanchez, P.Hernandez-Lopez, R.Flores-Solis, D.Saucedo-Yanez, A.L.Chavez-Uribe, I.Brieba, L.G.Del Rio-Portilla, F.

(2014) Chem.Res.Toxicol. 27: 960-967

  • DOI: 10.1021/tx4004193
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • The scorpion toxin tamapin displays the most potent and selective blockage against KCa2.2 channels known to date. In this work, we report the biosynthesis, three-dimensional structure, and cytotoxicity on cancer cell lines (Jurkat E6-1 and human mamm ...

    The scorpion toxin tamapin displays the most potent and selective blockage against KCa2.2 channels known to date. In this work, we report the biosynthesis, three-dimensional structure, and cytotoxicity on cancer cell lines (Jurkat E6-1 and human mammary breast cancer MDA-MB-231) of recombinant tamapin and five related peptides bearing mutations on residues (R6A,R7A, R13A, R6A-R7A, and GS-tamapin) that were previously suggested to be important for tamapin's activity. The indicated cell lines were used as they constitutively express KCa2.2 channels. The studied toxin-like peptides displayed lethal responses on Jurkat T cells and breast cancer cells; their effect is dose- and time-dependent with IC50 values in the nanomolar range. The order of potency is r-tamapin>GS-tamapin>R6A>R13A>R6A-R7A>R7A for Jurkat T cells and r-tamapin>R7A for MDA-MB-231 breast cancer cells. Our structural determination by NMR demonstrated that r-tamapin preserves the folding of the αKTx5 subfamily and that neither single nor double alanine mutations affect the three-dimensional structure of the wild-type peptide. In contrast, our activity assays show that changes in cytotoxicity are related to the chemical nature of certain residues. Our results suggest that the toxic activity of r-tamapin on Jurkat and breast cancer cells could be mediated by the interaction of charged residues in tamapin with KCa2.2 channels via the apoptotic cell death pathway.


    Organizational Affiliation

    Instituto de Química, Universidad Nacional Autónoma de México , Ciudad Universitaria, Circuito Exterior s/n, México, D.F. 04510, México.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Potassium channel toxin alpha-KTx 5.4
A
33Hottentotta tamulusMutation(s): 1 
Find proteins for P59869 (Hottentotta tamulus)
Go to UniProtKB:  P59869
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 200 
  • Conformers Submitted: 20 
  • Selection Criteria: structures with the least restraint violations 

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2014-05-28
    Type: Initial release
  • Version 1.1: 2014-07-02
    Type: Database references