The juxtamembrane region of TrkA kinase is critical for inhibitor selectivity

Bioorg Med Chem Lett. 2017 Mar 1;27(5):1233-1236. doi: 10.1016/j.bmcl.2017.01.056. Epub 2017 Jan 21.

Abstract

Although numerous crystal structures for protein kinases have been reported, many include only the kinase domain but not the juxtamembrane (JM) region, a critical activity-controlling segment of receptor tyrosine kinases (RTKs). In this study, we determined the X-ray crystal structure of the tropomyosin receptor kinase (Trk) A selective inhibitor A1 complexed with the TrkA kinase domain and the JM region. This structure revealed that the unique inhibitor-binding pocket created by a novel JM configuration yields significant potency and high selectivity against TrkB and TrkC. Moreover, we validated the importance of the JM region for the potency of A1 using in vitro assays. The introduction of moieties that interact with the JM region will be one of the most effective strategies for producing highly selective RTK inhibitors.

Keywords: Allosteric inhibitor; Crystal structure; Juxtamembrane region; TrkA; Tyrosine kinase inhibitor.

MeSH terms

  • Binding Sites
  • Biological Assay
  • Cell Membrane / enzymology
  • Crystallography, X-Ray
  • Enzyme Activation / drug effects
  • Hydrogen Bonding
  • Inhibitory Concentration 50
  • Membrane Proteins / chemistry*
  • Membrane Proteins / metabolism
  • Models, Molecular*
  • Molecular Structure
  • Protein Kinase Inhibitors / chemistry*
  • Protein Kinase Inhibitors / pharmacology
  • Protein Structure, Tertiary
  • Receptor, trkA / antagonists & inhibitors*
  • Receptor, trkA / chemistry*
  • Receptor, trkA / metabolism

Substances

  • Membrane Proteins
  • Protein Kinase Inhibitors
  • Receptor, trkA