2K9E

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 1.1 of the entry. See complete history

Literature

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: 10.1124/mol.108.052704

  • 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-term ...

    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.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Potassium channel toxin ShK
A
37Stichodactyla helianthusMutation(s): 1 
Find proteins for P29187 (Stichodactyla helianthus)
Go to UniProtKB:  P29187
Small Molecules
Modified Residues  3 Unique
IDChainsTypeFormula2D DiagramParent
NH2
Query on NH2
A
NON-POLYMERH2 N

--

PFX
Query on PFX
A
L-peptide NH3 amino terminusC15 H24 N2 O8 P

--

NLE
Query on NLE
A
L-PEPTIDE LINKINGC6 H13 N O2LEU
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 50 
  • Conformers Submitted: 20 
  • Selection Criteria: structures with the lowest energy 
  • Olderado: 2K9E Olderado

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

  • Deposited Date: 2008-10-09 
  • Released Date: 2009-01-20 
  • Deposition Author(s): Galea, C.A.

Revision History 

  • Version 1.0: 2009-01-20
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance