TABLE 4.

Effect of PA, LA, αLA, and SA on the oxygenation of AA by wild type and R120A muCOX-2

For the competition assay, results are expressed as the percent decrease in oxygenation of 20 μm AA in the presence of 100 μm 18-carbon fatty acid substrate relative to the oxygenation of 20 μm AA alone. For the activation assay, results are expressed as the percent increase in oxygenation of 20 μm AA in the presence of 100 μm PA relative to the oxygenation of 20 μm AA alone. Values are derived from triplicate determinations using an oxygen electrode (±S.E.).

Construct	Reduction in oxygenation of AA by			Activation of AA oxygenation by PA (16:0)
	LA (18:2 ω-6)	αLA (18:3 ω-3)	SA (18:4 ω-3)
	%			%
Wild type	22.4 ± 4.8	13.6 ± 1.7	22.1 ± 1.9	13.2 ± 0.8
R120A	43.3 ± 1.7	41.6 ± 2.5	23.5 ± 1.5	−1.1 ± 1.4