Arachidonic acid and selected other polyunsaturated fatty acids are stereoselectively oxygenated at carbon 5 by the non-heme iron containing enzyme 5-lipoxygenase (5-LO). The intervention of a second protein, 5-LO-activating protein (FLAP), is required before 5-LO can become catalytically active. MK-886 binds to FLAP with high-affinity and prevents 5-LO activation. MK-886 inhibits leukotriene biosynthesis in leukocytes with an IC50 of 2.5 nM. In human whole blood, leukotriene biosynthesis is inhibited by MK-886 with an IC50 of 1.1 μM.
