Crystal Structure of p38a Mitogen-Activated Protein Kinase in Complex with a Triazolopyridazinone inhibitor

Experimental Data Snapshot

  • Resolution: 2.15 Å
  • R-Value Free: 0.255 
  • R-Value Work: 0.234 
  • R-Value Observed: 0.235 

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Identification of triazolopyridazinones as potent p38alpha inhibitors.

Herberich, B.Jackson, C.Wurz, R.P.Pettus, L.H.Sherman, L.Liu, Q.Henkle, B.Saris, C.J.Wong, L.M.Chmait, S.Lee, M.R.Mohr, C.Hsieh, F.Tasker, A.S.

(2012) Bioorg Med Chem Lett 22: 1226-1229

  • DOI: https://doi.org/10.1016/j.bmcl.2011.11.067
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    Structure-activity relationship (SAR) investigations of a novel class of triazolopyridazinone p38α mitogen activated protein kinase (MAPK) inhibitors are disclosed. From these studies, increased in vitro potency was observed for 2,6-disubstituted phenyl moieties and N-ethyl triazolopyridazinone cores due to key contacts with Leu108, Ala157 and Val38. Further investigation led to the identification of three compounds, 3g, 3j and 3m that are highly potent inhibitors of LPS-induced MAPKAP kinase 2 (MK2) phosphorylation in 50% human whole blood (hWB), and possess desirable in vivo pharmacokinetic and kinase selectivity profiles.

  • Organizational Affiliation

    Department of Chemistry Research and Discovery, Amgen Inc., One Amgen Center Drive, Thousand Oaks, CA 91320, USA. brad.herberich@amgen.com

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Mitogen-activated protein kinase 14366Homo sapiensMutation(s): 0 
UniProt & NIH Common Fund Data Resources
Find proteins for Q16539 (Homo sapiens)
Explore Q16539 
Go to UniProtKB:  Q16539
PHAROS:  Q16539
GTEx:  ENSG00000112062 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ16539
Sequence Annotations
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
Query on 09J

Download Ideal Coordinates CCD File 
B [auth A]3-[3-(2-chloro-6-fluorophenyl)-5-ethyl-6-oxo-5,6-dihydro[1,2,4]triazolo[4,3-b]pyridazin-7-yl]-N-cyclopropyl-4-methylbenzamide
C24 H21 Cl F N5 O2
Binding Affinity Annotations 
IDSourceBinding Affinity
09J BindingDB:  3U8W IC50: min: 1, max: 4.9 (nM) from 3 assay(s)
PDBBind:  3U8W IC50: 1 (nM) from 1 assay(s)
Binding MOAD:  3U8W IC50: 1 (nM) from 1 assay(s)
Experimental Data & Validation

Experimental Data

  • Resolution: 2.15 Å
  • R-Value Free: 0.255 
  • R-Value Work: 0.234 
  • R-Value Observed: 0.235 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 45.143α = 90
b = 85.789β = 90
c = 120.569γ = 90
Software Package:
Software NamePurpose
JDirectordata collection
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

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Ligand Structure Quality Assessment 

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2012-08-29
    Type: Initial release
  • Version 1.1: 2024-02-28
    Changes: Data collection, Database references, Derived calculations