4Z7P

X-ray structure of racemic ShK Q16K toxin


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.20 Å
  • R-Value Free: 0.227 
  • R-Value Work: 0.204 
  • R-Value Observed: 0.205 

wwPDB Validation   3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Pharmaceutical Optimization of Peptide Toxins for Ion Channel Targets: Potent, Selective, and Long-Lived Antagonists of Kv1.3.

Murray, J.K.Qian, Y.X.Liu, B.Elliott, R.Aral, J.Park, C.Zhang, X.Stenkilsson, M.Salyers, K.Rose, M.Li, H.Yu, S.Andrews, K.L.Colombero, A.Werner, J.Gaida, K.Sickmier, E.A.Miu, P.Itano, A.McGivern, J.Gegg, C.V.Sullivan, J.K.Miranda, L.P.

(2015) J Med Chem 58: 6784-6802

  • DOI: 10.1021/acs.jmedchem.5b00495
  • Primary Citation of Related Structures:  
    4Z7P

  • PubMed Abstract: 
  • To realize the medicinal potential of peptide toxins, naturally occurring disulfide-rich peptides, as ion channel antagonists, more efficient pharmaceutical optimization technologies must be developed. Here, we show that the therapeutic properties of multiple cysteine toxin peptides can be rapidly and substantially improved by combining direct chemical strategies with high-throughput electrophysiology ...

    To realize the medicinal potential of peptide toxins, naturally occurring disulfide-rich peptides, as ion channel antagonists, more efficient pharmaceutical optimization technologies must be developed. Here, we show that the therapeutic properties of multiple cysteine toxin peptides can be rapidly and substantially improved by combining direct chemical strategies with high-throughput electrophysiology. We applied whole-molecule, brute-force, structure-activity analoging to ShK, a peptide toxin from the sea anemone Stichodactyla helianthus that inhibits the voltage-gated potassium ion channel Kv1.3, to effectively discover critical structural changes for 15× selectivity against the closely related neuronal ion channel Kv1.1. Subsequent site-specific polymer conjugation resulted in an exquisitely selective Kv1.3 antagonist (>1000× over Kv1.1) with picomolar functional activity in whole blood and a pharmacokinetic profile suitable for weekly administration in primates. The pharmacological potential of the optimized toxin peptide was demonstrated by potent and sustained inhibition of cytokine secretion from T cells, a therapeutic target for autoimmune diseases, in cynomolgus monkeys.


    Organizational Affiliation

    Therapeutic Discovery, Amgen Inc. , 360 Binney Street, Cambridge, Massachusetts 02142, United States.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Potassium channel toxin kappa-stichotoxin-She1aA35Stichodactyla helianthusMutation(s): 1 
UniProt
Find proteins for P29187 (Stichodactyla helianthus)
Explore P29187 
Go to UniProtKB:  P29187
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.20 Å
  • R-Value Free: 0.227 
  • R-Value Work: 0.204 
  • R-Value Observed: 0.205 
  • Space Group: H -3
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 60.783α = 90
b = 60.783β = 90
c = 43.592γ = 120
Software Package:
Software NamePurpose
SCALEPACKdata scaling
PHASERphasing
REFMACrefinement
PDB_EXTRACTdata extraction
HKL-2000data reduction

Structure Validation

View Full Validation Report




Entry History 

Deposition Data

  • Deposited Date: 2015-04-07 
  • Released Date: 2015-09-09 
  • Deposition Author(s): Sickmier, E.A.

Revision History  (Full details and data files)

  • Version 1.0: 2015-09-09
    Type: Initial release
  • Version 1.1: 2015-09-23
    Changes: Database references