6QBS

The Alkyne Moiety as a Latent Electrophile in Irreversible Covalent Small Molecule Inhibitors of Cathepsin K


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Free: 0.210 
  • R-Value Work: 0.204 
  • R-Value Observed: 0.204 

Starting Model: experimental
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This is version 1.4 of the entry. See complete history


Literature

The Alkyne Moiety as a Latent Electrophile in Irreversible Covalent Small Molecule Inhibitors of Cathepsin K.

Mons, E.Jansen, I.D.C.Loboda, J.van Doodewaerd, B.R.Hermans, J.Verdoes, M.van Boeckel, C.A.A.van Veelen, P.A.Turk, B.Turk, D.Ovaa, H.

(2019) J Am Chem Soc 141: 3507-3514

  • DOI: https://doi.org/10.1021/jacs.8b11027
  • Primary Citation of Related Structures:  
    6QBS

  • PubMed Abstract: 

    Irreversible covalent inhibitors can have a beneficial pharmacokinetic/pharmacodynamics profile but are still often avoided due to the risk of indiscriminate covalent reactivity and the resulting adverse effects. To overcome this potential liability, we introduced an alkyne moiety as a latent electrophile into small molecule inhibitors of cathepsin K (CatK). Alkyne-based inhibitors do not show indiscriminate thiol reactivity but potently inhibit CatK protease activity by formation of an irreversible covalent bond with the catalytic cysteine residue, confirmed by crystal structure analysis. The rate of covalent bond formation ( k inact ) does not correlate with electrophilicity of the alkyne moiety, indicative of a proximity-driven reactivity. Inhibition of CatK-mediated bone resorption is validated in human osteoclasts. Together, this work illustrates the potential of alkynes as latent electrophiles in small molecule inhibitors, enabling the development of irreversible covalent inhibitors with an improved safety profile.


  • Organizational Affiliation

    Department of Cell and Chemical Biology, Oncode Institute , Leiden University Medical Center , 2300 RC Leiden , The Netherlands.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Cathepsin K
A, B
215Homo sapiensMutation(s): 0 
Gene Names: CTSKCTSOCTSO2
EC: 3.4.22.38
UniProt & NIH Common Fund Data Resources
Find proteins for P43235 (Homo sapiens)
Explore P43235 
Go to UniProtKB:  P43235
PHAROS:  P43235
GTEx:  ENSG00000143387 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP43235
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Free: 0.210 
  • R-Value Work: 0.204 
  • R-Value Observed: 0.204 
  • Space Group: P 61 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 75.35α = 90
b = 75.35β = 90
c = 340.2γ = 120
Software Package:
Software NamePurpose
MAINrefinement
XDSdata reduction
Aimlessdata scaling
MOLREPphasing

Structure Validation

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Ligand Structure Quality Assessment 


Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
Slovenian Research AgencySlovenia--
Netherlands Organisation for Scientific ResearchNetherlands--

Revision History  (Full details and data files)

  • Version 1.0: 2019-02-06
    Type: Initial release
  • Version 1.1: 2019-03-06
    Changes: Data collection, Database references
  • Version 1.2: 2019-04-03
    Changes: Data collection
  • Version 1.3: 2024-01-24
    Changes: Advisory, Data collection, Database references, Derived calculations, Refinement description
  • Version 1.4: 2024-10-09
    Changes: Structure summary