Shk-dnp22: A Potent Kv1.3-specific immunosuppressive polypeptide, NMR, 20 structures

Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 50 
  • Conformers Submitted: 20 

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ShK-Dap22, a potent Kv1.3-specific immunosuppressive polypeptide.

Kalman, K.Pennington, M.W.Lanigan, M.D.Nguyen, A.Rauer, H.Mahnir, V.Paschetto, K.Kem, W.R.Grissmer, S.Gutman, G.A.Christian, E.P.Cahalan, M.D.Norton, R.S.Chandy, K.G.

(1998) J Biol Chem 273: 32697-32707

  • DOI: https://doi.org/10.1074/jbc.273.49.32697
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    The voltage-gated potassium channel in T lymphocytes, Kv1.3, is an important molecular target for immunosuppressive agents. A structurally defined polypeptide, ShK, from the sea anemone Stichodactyla helianthus inhibited Kv1.3 potently and also blocked Kv1.1, Kv1.4, and Kv1.6 at subnanomolar concentrations. Using mutant cycle analysis in conjunction with complementary mutagenesis of ShK and Kv1.3, and utilizing the structure of ShK, we determined a likely docking configuration for this peptide in the channel. Based upon this topological information, we replaced the critical Lys22 in ShK with the positively charged, non-natural amino acid diaminopropionic acid (ShK-Dap22) and generated a highly selective and potent blocker of the T-lymphocyte channel. ShK-Dap22, at subnanomolar concentrations, suppressed anti-CD3 induced human T-lymphocyte [3H]thymidine incorporation in vitro. Toxicity with this mutant peptide was low in a rodent model, with a median paralytic dose of approximately 200 mg/kg body weight following intravenous administration. The overall structure of ShK-Dap22 in solution, as determined from NMR data, is similar to that of native ShK toxin, but there are some differences in the residues involved in potassium channel binding. Based on these results, we propose that ShK-Dap22 or a structural analogue may have use as an immunosuppressant for the prevention of graft rejection and for the treatment of autoimmune diseases.

  • Organizational Affiliation

    Departments of Physiology & Biophysics, and Microbiology and Molecular Genetics, University of California, Irvine, California 92697-4560, USA.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
POTASSIUM CHANNEL TOXIN SHK35Stichodactyla helianthusMutation(s): 1 
Find proteins for P29187 (Stichodactyla helianthus)
Explore P29187 
Go to UniProtKB:  P29187
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP29187
Sequence Annotations
  • Reference Sequence
Small Molecules
Modified Residues  1 Unique
IDChains TypeFormula2D DiagramParent
Query on DNP
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 50 
  • Conformers Submitted: 20 

Structure Validation

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Entry History 

Revision History  (Full details and data files)

  • Version 1.0: 1998-12-02
    Type: Initial release
  • Version 1.1: 2008-03-21
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2022-02-16
    Changes: Database references, Derived calculations, Other
  • Version 1.4: 2022-12-21
    Changes: Database references