Inspecting the structure-activity relationship of protein kinase CK2 inhibitors derived from tetrabromo-benzimidazole

Chem Biol. 2005 Nov;12(11):1211-9. doi: 10.1016/j.chembiol.2005.08.015.


CK2 is a very pleiotropic protein kinase whose high constitutive activity is suspected to cooperate to neoplasia. Here, the crystal structure of the complexes between CK2 and three selective tetrabromo-benzimidazole derivatives inhibiting CK2 with Ki values between 40 and 400 nM are presented. The ligands bind to the CK2 active site in a different way with respect to the parent compound TBB. They enter more deeply into the cavity, establishing halogen bonds with the backbone of Glu114 and Val116 in the hinge region. A detailed analysis of the interactions highlights a major role of the hydrophobic effect in establishing the rank of potency within this class of inhibitors and shows that polar interactions are responsible for the different orientation of the molecules in the active site.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Benzimidazoles / chemistry*
  • Benzimidazoles / pharmacology*
  • Bromine / chemistry*
  • Casein Kinase II / antagonists & inhibitors*
  • Casein Kinase II / genetics
  • Casein Kinase II / metabolism
  • Humans
  • Hydrophobic and Hydrophilic Interactions
  • Inhibitory Concentration 50
  • Models, Molecular
  • Molecular Structure
  • Mutation / genetics
  • Phosphorylation / drug effects
  • Protein Kinase Inhibitors / chemistry*
  • Protein Kinase Inhibitors / pharmacology*
  • Structure-Activity Relationship


  • 4,5,6,7-tetrabromobenzimidazole
  • Benzimidazoles
  • Protein Kinase Inhibitors
  • benzimidazole
  • Casein Kinase II
  • Bromine

Associated data

  • PDB/1ZOE
  • PDB/1ZOG
  • PDB/1ZOH