Validation and Invalidation of Chemical Probes for the Human N-myristoyltransferases

Cell Chem Biol. 2019 Jun 20;26(6):892-900.e4. doi: 10.1016/j.chembiol.2019.03.006. Epub 2019 Apr 18.


On-target, cell-active chemical probes are of fundamental importance in chemical and cell biology, whereas poorly characterized probes often lead to invalid conclusions. Human N-myristoyltransferase (NMT) has attracted increasing interest as target in cancer and infectious diseases. Here we report an in-depth comparison of five compounds widely applied as human NMT inhibitors, using a combination of quantitative whole-proteome N-myristoylation profiling, biochemical enzyme assays, cytotoxicity, in-cell protein synthesis, and cell-cycle assays. We find that N-myristoylation is unaffected by 2-hydroxymyristic acid (100 μM), D-NMAPPD (30 μM), or Tris-DBA palladium (10 μM), with the latter compounds causing cytotoxicity through mechanisms unrelated to NMT. In contrast, drug-like inhibitors IMP-366 (DDD85646) and IMP-1088 delivered complete and specific inhibition of N-myristoylation in a range of cell lines at 1 μM and 100 nM, respectively. This study enables the selection of appropriate on-target probes for future studies and suggests the need for reassessment of previous studies that used off-target compounds.

Keywords: 2-hydroxymyristic acid; D-NMAPPD (B13); IMP-1088; IMP-366 (DDD85646); N-myristoylation; N-myristoyltransferases (NMT); Tris-DBA palladium; chemical proteomics; metabolic tagging; sortase A ligation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acyltransferases / antagonists & inhibitors*
  • Acyltransferases / metabolism
  • Antineoplastic Agents / chemistry
  • Antineoplastic Agents / pharmacology*
  • Apoptosis / drug effects
  • Cell Cycle / drug effects
  • Cell Line, Tumor
  • Cell Proliferation / drug effects
  • Cell Survival / drug effects
  • Dose-Response Relationship, Drug
  • Drug Screening Assays, Antitumor
  • Enzyme Inhibitors / chemistry
  • Enzyme Inhibitors / pharmacology*
  • Humans
  • Molecular Structure
  • Myristic Acids / chemistry
  • Myristic Acids / pharmacology*
  • Structure-Activity Relationship


  • Antineoplastic Agents
  • Enzyme Inhibitors
  • Myristic Acids
  • alpha-hydroxymyristic acid
  • Acyltransferases
  • glycylpeptide N-tetradecanoyltransferase