Macromolecule Content

• Total Structure Weight: 4423.18 
• Atom Count: 303 
• Residue Count: 37 
• Unique protein chains: 1

2K9E

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

• DOI: 10.2210/pdb2K9E/pdb
• BMRB: 15983

• Classification: TOXIN
• Organism(s): Stichodactyla helianthus
• Mutation(s): 1 


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

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Experimental Data Snapshot

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

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

• PubMed: 19122005 
• 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-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.

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Organizational Affiliation: 

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

Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details
Potassium channel toxin ShK	A	37	Stichodactyla helianthus	Mutation(s): 1
Find proteins for P29187 (Stichodactyla helianthus) Go to UniProtKB:  P29187

Small Molecules

Modified Residues  3 Unique
ID	Chains	Type	Formula	2D Diagram	Parent
NH2	A	NON-POLYMER	H2 N		--
PFX	A	L-peptide NH3 amino terminus	C15 H24 N2 O8 P		--
NLE	A	L-PEPTIDE LINKING	C6 H13 N O2		LEU

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

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