5-Lipoxygenase-activating protein is the target of a novel hybrid of two classes of leukotriene biosynthesis inhibitors.
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.
Mancini
J A
JA
Department of Pharmacology, Merck Frosst Centre for Therapeutic Research, Pointe Claire-Dorval, Quebec, Canada.
Prasit
P
P
Coppolino
M G
MG
Charleson
P
P
Leger
S
S
Evans
J F
JF
Gillard
J W
JW
Vickers
P J
PJ
D058927:5-Lipoxygenase-Activating Proteins; D001386:Azides / Q000378:metabolism / Q000494:pharmacology; D001667:Binding, Competitive; D002352:Carrier Proteins / Q000187:drug effects / Q000378:metabolism*; D002478:Cells, Cultured; D006801:Humans; D007211:Indoles / Q000378:metabolism* / Q000494:pharmacology; D007457:Iodine Radioisotopes; D020024:Leukotriene Antagonists; D015289:Leukotrienes / Q000096:biosynthesis*; D008565:Membrane Proteins / Q000187:drug effects / Q000378:metabolism*; D009504:Neutrophils / Q000187:drug effects / Q000378:metabolism; D011804:Quinolines / Q000378:metabolism* / Q000494:pharmacology; D002722:Chlorobenzenes
D058927:5-Lipoxygenase-Activating Proteins; D001386:Azides; D002352:Carrier Proteins; D007211:Indoles; D007457:Iodine Radioisotopes; D020024:Leukotriene Antagonists; D015289:Leukotrienes; D008565:Membrane Proteins; D011804:Quinolines; C548592:ALOX5AP protein, human; C060893:MK-886; D002722:Chlorobenzenes; C071988:L 674573; C062610:L 669083; C073122:L 691678