Flexibility of the NSAID binding site in the structure of human cyclooxygenase-2

Nat Struct Biol. 1996 Nov;3(11):927-33. doi: 10.1038/nsb1196-927.


The first crystal structure of human cyclooxygenase-2, in the presence of a selective inhibitor, is similar to that of cyclooxygenase-1. The structure of the NSAID binding site is also well conserved, although there are differences in its overall size and shape which may be exploited for the further development of selective COX-2 inhibitors. A second COX-2 structure with a different bound inhibitor displays a new, open conformation at the bottom of the NSAID binding site, without significant changes in other regions of the COX-2 structure. These two COX-2 structures provide evidence for the flexible nature of cyclooxygenase, revealing details about how substrate and inhibitor may gain access to the cyclooxygenase active site from within the membrane.

MeSH terms

  • Anti-Inflammatory Agents, Non-Steroidal / metabolism*
  • Binding Sites
  • Crystallization
  • Crystallography, X-Ray
  • Cyclooxygenase 1
  • Cyclooxygenase 2
  • Cyclooxygenase 2 Inhibitors
  • Cyclooxygenase Inhibitors / metabolism*
  • Enzyme Inhibitors / metabolism
  • Humans
  • Isoenzymes / chemistry*
  • Isoenzymes / metabolism
  • Membrane Proteins
  • Models, Molecular
  • Prostaglandin-Endoperoxide Synthases / chemistry*
  • Prostaglandin-Endoperoxide Synthases / metabolism
  • Protein Conformation
  • Protein Structure, Tertiary


  • Anti-Inflammatory Agents, Non-Steroidal
  • Cyclooxygenase 2 Inhibitors
  • Cyclooxygenase Inhibitors
  • Enzyme Inhibitors
  • Isoenzymes
  • Membrane Proteins
  • Cyclooxygenase 1
  • Cyclooxygenase 2
  • PTGS1 protein, human
  • PTGS2 protein, human
  • Prostaglandin-Endoperoxide Synthases