PT - JOURNAL ARTICLE AU - J A Mancini AU - P Prasit AU - M G Coppolino AU - P Charleson AU - S Leger AU - J F Evans AU - J W Gillard AU - P J Vickers TI - 5-Lipoxygenase-activating protein is the target of a novel hybrid of two classes of leukotriene biosynthesis inhibitors. DP - 1992 Feb 01 TA - Molecular Pharmacology PG - 267--272 VI - 41 IP - 2 4099 - http://molpharm.aspetjournals.org/content/41/2/267.short 4100 - http://molpharm.aspetjournals.org/content/41/2/267.full SO - Mol Pharmacol1992 Feb 01; 41 AB - An 18-kDa leukocyte membrane protein, termed 5-lipoxygenase-activating protein (FLAP), has recently been shown to be the target of two structurally distinct classes of leukotriene biosynthesis inhibitors. These classes of inhibitors are based on indole and quinoline structures and are represented by MK-886 and L-674,573, respectively. A novel class of hybrid structure based on the indole and quinoline classes of inhibitors, termed quindoles, has recently been developed. These compounds, exemplified by L-689,037, are potent inhibitors of leukotriene biosynthesis, both in vitro and in vivo. In the present study, we have developed and characterized a potent radioiodinated photoaffinity analogue of L-689,037, termed [125I]L-691,678. This compound was used in immunoprecipitation studies with FLAP antisera to show that the quindole series of leukotriene biosynthesis inhibitors interact directly with FLAP. In addition, we show that MK-886, L-674,573, and L-689,037 specifically compete, in a concentration-dependent manner, with both [125I]L-691,678 and [125I]L-669,083, a photoaffinity analogue of MK-886, for binding to FLAP. These results suggest that these three classes of leukotriene biosynthesis inhibitors share a common binding site on FLAP, providing further evidence that FLAP represents a suitable target for structurally diverse classes of leukotriene biosynthesis inhibitors.