NMR Solution Structure for ShK-192: A Potent KV1.3-Specific Immunosuppressive Polypeptide

Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 50 
  • Conformers Submitted: 20 
  • Selection Criteria: structures with the lowest energy 

wwPDB Validation   3D Report Full Report

This is version 3.0 of the entry. See complete history


Engineering a stable and selective peptide blocker of the Kv1.3 channel in T lymphocytes

Pennington, M.W.Beeton, C.Galea, C.A.Smith, B.J.Chi, V.Monaghan, K.P.Garcia, A.Rangaraju, S.Giuffrida, A.Plank, D.Crossley, G.Nugent, D.Khaytin, I.Lefievre, Y.Peshenko, I.Dixon, C.Chauhan, S.Orzel, A.Inoue, T.Hu, X.Moore, R.V.Norton, R.S.Chandy, K.G.

(2009) Mol Pharmacol 75: 762-773

  • DOI: https://doi.org/10.1124/mol.108.052704
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    Kv1.3 potassium channels maintain the membrane potential of effector memory (T(EM)) T cells that are important mediators of multiple sclerosis, type 1 diabetes mellitus, and rheumatoid arthritis. The polypeptide ShK-170 (ShK-L5), containing an N-terminal phosphotyrosine extension of the Stichodactyla helianthus ShK toxin, is a potent and selective blocker of these channels. However, a stability study of ShK-170 showed minor pH-related hydrolysis and oxidation byproducts that were exacerbated by increasing temperatures. We therefore engineered a series of analogs to minimize the formation of these byproducts. The analog with the greatest stability, ShK-192, contains a nonhydrolyzable phosphotyrosine surrogate, a methionine isostere, and a C-terminal amide. ShK-192 shows the same overall fold as ShK, and there is no evidence of any interaction between the N-terminal adduct and the rest of the peptide. The docking configuration of ShK-192 in Kv1.3 shows the N-terminal para-phosphonophenylalanine group lying at the junction of two channel monomers to form a salt bridge with Lys(411) of the channel. ShK-192 blocks Kv1.3 with an IC(50) of 140 pM and exhibits greater than 100-fold selectivity over closely related channels. After a single subcutaneous injection of 100 microg/kg, approximately 100 to 200 pM concentrations of active peptide is detectable in the blood of Lewis rats 24, 48, and 72 h after the injection. ShK-192 effectively inhibits the proliferation of T(EM) cells and suppresses delayed type hypersensitivity when administered at 10 or 100 microg/kg by subcutaneous injection once daily. ShK-192 has potential as a therapeutic for autoimmune diseases mediated by T(EM) cells.

  • Organizational Affiliation

    Bachem Bioscience Inc., King of Prussia, Pennsylvania, USA.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Kappa-stichotoxin-She3a38Stichodactyla helianthusMutation(s): 2 
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  2 Unique
IDChains TypeFormula2D DiagramParent
Query on NLE
Query on ZV4
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 50 
  • Conformers Submitted: 20 
  • Selection Criteria: structures with the lowest energy 

Structure Validation

View Full Validation Report

Entry History 

Deposition Data

  • Released Date: 2009-01-20 
  • Deposition Author(s): Galea, C.A.

Revision History  (Full details and data files)

  • Version 1.0: 2009-01-20
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance
  • Version 1.2: 2020-02-26
    Changes: Data collection, Database references, Derived calculations, Other
  • Version 1.3: 2021-11-10
    Changes: Database references
  • Version 2.0: 2023-04-19
    Changes: Advisory, Atomic model, Database references, Derived calculations, Experimental preparation, Non-polymer description, Polymer sequence, Source and taxonomy, Structure summary
  • Version 3.0: 2023-11-15
    Changes: Advisory, Atomic model, Data collection, Derived calculations