Halogen bonds involved in binding of halogenated ligands by protein kinases

Acta Biochim Pol. 2016;63(2):203-14. doi: 10.18388/abp.2015_1106. Epub 2016 Apr 20.

Abstract

Analysis of 664 known structures of protein kinase complexes with halogenated ligands revealed 424 short contacts between a halogen atom and a potential protein X-bond acceptor, the topology and geometry of which were analyzed according to the type of a halogen atom (X = Cl, Br, I) and a putative protein X-bond acceptor. Among 236 identified halogen bonds, the most represented ones are directed to backbone carbonyls of the hinge region and may replace the pattern of ATP-like hydrogen bonds. Some halogen-π interactions with either aromatic residues or peptide bonds, that accompany the interaction with the hinge region, may possibly enhance ligand selectivity. Interestingly, many of these halogen-π interactions are bifurcated. Geometrical preferences identify iodine as the strongest X-bond donor, less so bromine, while virtually no such preferences were observed for chlorine; and a backbone carbonyl as the strongest X-bond acceptor. The presence of a halogen atom in a ligand additionally affects the properties of proximal hydrogen bonds, which according to geometrical parameters get strengthened, when a nitrogen of a halogenated ligand acts as the hydrogen bond donor.

Publication types

  • Review

MeSH terms

  • Catalytic Domain
  • Halogens / chemistry*
  • Humans
  • Hydrogen Bonding
  • Ligands
  • Models, Molecular
  • Protein Binding
  • Protein Kinase Inhibitors / chemistry
  • Protein Kinase Inhibitors / pharmacology
  • Protein Kinase Inhibitors / therapeutic use
  • Protein Kinases / chemistry*
  • Protein Processing, Post-Translational

Substances

  • Halogens
  • Ligands
  • Protein Kinase Inhibitors
  • Protein Kinases