Novel Macrocyclic Peptidomimetics Targeting the Polo-Box Domain of Polo-Like Kinase 1

J Med Chem. 2022 Feb 10;65(3):1915-1932. doi: 10.1021/acs.jmedchem.1c01359. Epub 2022 Jan 14.


The polo-box domain (PBD) of Plk1 is a promising target for cancer therapeutics. We designed and synthesized novel phosphorylated macrocyclic peptidomimetics targeting PBD based on acyclic phosphopeptide PMQSpTPL. The inhibitory activities of 16e on Plk1-PBD is >30-fold higher than those of PMQSpTPL. Both 16a and 16e possess excellent selectivity for Plk1-PBD over Plk2/3-PBD. Analysis of the cocrystal structure of Plk1-PBD in complex with 16a reveals that the 3-(trifluoromethyl)benzoyl group in 16a interacts with Arg516 through a π-stacking interaction. This π-stacking interaction, which has not been reported previously, provides insight into the design of novel and potent Plk1-PBD inhibitors. Furthermore, 16h, a PEGlyated macrocyclic phosphopeptide derivative, induces Plk1 delocalization and mitotic failure in HeLa cells. Also, the number of phospho-H3-positive cells in a zebrafish embryo increases in proportion to the amount of 16a. Collectively, the novel macrocyclic peptidomimetics should serve as valuable templates for the design of potent and novel Plk1-PBD inhibitors.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Cycle Proteins / antagonists & inhibitors*
  • Cell Cycle Proteins / chemistry
  • Cell Cycle Proteins / metabolism
  • HEK293 Cells
  • HeLa Cells
  • Humans
  • Molecular Docking Simulation
  • Molecular Structure
  • Peptides, Cyclic / chemical synthesis
  • Peptides, Cyclic / metabolism
  • Peptides, Cyclic / pharmacology*
  • Peptidomimetics / chemical synthesis
  • Peptidomimetics / metabolism
  • Peptidomimetics / pharmacology*
  • Protein Binding
  • Protein Domains
  • Protein Kinase Inhibitors / chemical synthesis
  • Protein Kinase Inhibitors / metabolism
  • Protein Kinase Inhibitors / pharmacology*
  • Protein Serine-Threonine Kinases / antagonists & inhibitors*
  • Protein Serine-Threonine Kinases / chemistry
  • Protein Serine-Threonine Kinases / metabolism
  • Proto-Oncogene Proteins / antagonists & inhibitors*
  • Proto-Oncogene Proteins / chemistry
  • Proto-Oncogene Proteins / metabolism
  • Structure-Activity Relationship
  • Zebrafish


  • Cell Cycle Proteins
  • Peptides, Cyclic
  • Peptidomimetics
  • Protein Kinase Inhibitors
  • Proto-Oncogene Proteins
  • Protein Serine-Threonine Kinases
  • polo-like kinase 1