An Alkynylpyrimidine-Based Covalent Inhibitor That Targets a Unique Cysteine in NF-κB-Inducing Kinase

J Med Chem. 2021 Jul 22;64(14):10001-10018. doi: 10.1021/acs.jmedchem.0c01249. Epub 2021 Jul 2.

Abstract

NF-κB-inducing kinase (NIK) is a key enzyme in the noncanonical NF-κB pathway, of interest in the treatment of a variety of diseases including cancer. Validation of NIK as a drug target requires potent and selective inhibitors. The protein contains a cysteine residue at position 444 in the back pocket of the active site, unique within the kinome. Analysis of existing inhibitor scaffolds and early structure-activity relationships (SARs) led to the design of C444-targeting covalent inhibitors based on alkynyl heterocycle warheads. Mass spectrometry provided proof of the covalent mechanism, and the SAR was rationalized by computational modeling. Profiling of more potent analogues in tumor cell lines with constitutively activated NIK signaling induced a weak antiproliferative effect, suggesting that kinase inhibition may have limited impact on cancer cell growth. This study shows that alkynyl heterocycles are potential cysteine traps, which may be employed where common Michael acceptors, such as acrylamides, are not tolerated.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkynes / chemical synthesis
  • Alkynes / chemistry
  • Alkynes / pharmacology*
  • Cysteine / chemistry
  • Cysteine / pharmacology*
  • Dose-Response Relationship, Drug
  • Humans
  • Molecular Structure
  • NF-kappaB-Inducing Kinase
  • Protein Kinase Inhibitors / chemical synthesis
  • Protein Kinase Inhibitors / chemistry
  • Protein Kinase Inhibitors / pharmacology*
  • Protein Serine-Threonine Kinases / antagonists & inhibitors*
  • Protein Serine-Threonine Kinases / metabolism
  • Pyrimidines / chemical synthesis
  • Pyrimidines / chemistry
  • Pyrimidines / pharmacology*
  • Structure-Activity Relationship

Substances

  • Alkynes
  • Protein Kinase Inhibitors
  • Pyrimidines
  • Protein Serine-Threonine Kinases
  • Cysteine
  • pyrimidine