Structure-based design of novel Chk1 inhibitors: insights into hydrogen bonding and protein-ligand affinity.
We report the discovery, synthesis, and crystallographic binding mode of novel furanopyrimidine and pyrrolopyrimidine inhibitors of the Chk1 kinase, an oncology target. These inhibitors are synthetically tractable and inhibit Chk1 by competing for its ATP site. A chronological account allows an objective comparison of modeled compound docking modes to the subsequently obtained crystal structures. The comparison provides insights regarding the interpretation of modeling results, in relationship to the multiple reasonable docking modes which may be obtained in a kinase-ATP site. The crystal structures were used to guide medicinal chemistry efforts. This led to a thorough characterization of a pair of ligand-protein complexes which differ by a single hydrogen bond. An analysis indicates that this hydrogen bond is expected to contribute a fraction of the 10-fold change in binding affinity, adding a valuable observation to the debate about the energetic role of hydrogen bonding in molecular recognition.
Vernalis (R&D) Limited, Granta Park, Abington, Cambridge CB1 6GB, UK. n.foloppe@vernalis.com
Nicolas
N
Foloppe
Lisa M
LM
Fisher
Rob
R
Howes
Peter
P
Kierstan
Andrew
A
Potter
Alan G S
AG
Robertson
Allan E
AE
Surgenor
D000255:Adenosine Triphosphate / Q000378:metabolism; D001665:Binding Sites; D001667:Binding, Competitive; D000071877:Checkpoint Kinase 1; D018360:Crystallography, X-Ray; D015195:Drug Design; D004791:Enzyme Inhibitors / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D006801:Humans; D006860:Hydrogen Bonding; D007700:Kinetics; D008024:Ligands; D008958:Models, Molecular; D008968:Molecular Conformation; D011487:Protein Conformation; D047428:Protein Kinase Inhibitors / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D011494:Protein Kinases / Q000737:chemistry / Q000378:metabolism*; D011743:Pyrimidines / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*
D004791:Enzyme Inhibitors; D008024:Ligands; D047428:Protein Kinase Inhibitors; D011743:Pyrimidines; D000255:Adenosine Triphosphate; D011494:Protein Kinases; C000605867:CHEK1 protein, human; D000071877:Checkpoint Kinase 1