Table 4.

Comparison of ligands bound in the monomers of the biological dimer of ovPGHS-1.

	Monomer A				Monomer B
ovPGHS-1 Structure	Ligand	Relative Occupancy	Conformation Of Dimer Interface Residues 123-129	Side Pocket Residues 510-515	Ligand	Relative Occupancy	Conformation of Dimer Interface Residues 123-129	Side Pocket Residues 510-515
1. Unoccupied	Glycerol	1.0	upa	Xb	None	0	up	Yc
2. Celecoxib (15)f	Celecoxib	1.0	up	X	Celecoxib	0.5	up/downd	X
3. Flurbiprofen (R120Q/Native)g	Flurbiprofen	1.0	up	X	Water or Flubiprofen	1.0 0.25	up/down	X
4. Nimesulideh	Nimesulide	1.0	up	X	Nimesulide	1.0	up	X
5. Diclofenac/ASA co-complexi	Diclofenac	1.0	up	Combination of X and Ze	ASA Diclofenac	0.8 0.2	up	X

^a“up” means a single conformation is present at dimer interface (i.e. the “up” conformation only).

^bX is the conformation most commonly observed in crystal structures (Figs. 2B and 6B).

^cY is a conformation deviating most from the commonly observed Conformation X (Figs. 2B and 6B).

^d“up/down” means two conformations are present at the dimer interface (i.e. an “up” and a “down” conformation).

^eZ is an alternative conformation slightly different from X and Y.

^fActivity tested with one mole of celecoxib per mole of ovPGHS-1 dimer resulted in no loss of cyclooxygenase activity (15).

^gActivity tested with an excess of flurbiprofen resulted in complete inhibition of cyclooxygenase activity.

^hActivity tested with an excess of nimesulide resulted in no loss in cyclooxygenase activity (15).

ⁱActivity tested with acetylated ovPGHS-1 (maximum acetylation of one mole of [1-¹⁴C-acetyl] per mole of ovPGHS-1 dimer) resulted in complete inhibition of cyclooxygenase activity (15).