title: A Single Amino Acid Difference between Mouse and Human 5-Lipoxygenase Activating Protein (FLAP) Explains the Speciation and Differential Pharmacology of Novel FLAP Inhibitors.
abstract: 5-Lipoxygenase activating protein (FLAP) plays a critical role in the metabolism of arachidonic acid to leukotriene A4, the precursor to the potent pro-inflammatory mediators leukotriene B4 and leukotriene C4 Studies with small molecule inhibitors of FLAP have led to the discovery of a drug binding pocket on the protein surface, and several pharmaceutical companies have developed compounds and performed clinical trials. Crystallographic studies and mutational analyses have contributed to a general understanding of compound binding modes. During our own efforts, we identified two unique chemical series. One series demonstrated strong inhibition of human FLAP but differential pharmacology across species and was completely inactive in assays with mouse or rat FLAP. The other series was active across rodent FLAP, as well as human and dog FLAP. Comparison of rodent and human FLAP amino acid sequences together with an analysis of a published crystal structure led to the identification of amino acid residue 24 in the floor of the putative binding pocket as a likely candidate for the observed speciation. On that basis, we tested compounds for binding to human G24A and mouse A24G FLAP mutant variants and compared the data to that generated for wild type human and mouse FLAP. These studies confirmed that a single amino acid mutation was sufficient to reverse the speciation observed in wild type FLAP. In addition, a PK/PD method was established in canines to enable preclinical profiling of mouse-inactive compounds.
authors.affiliation: Discovery Sciences, Janssen Research and Development, San Diego, California 92121.
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Blevitt
authors.affiliation: Discovery Sciences, Janssen Research and Development, San Diego, California 92121.
authors.forename: Michael D
authors.initials: MD
authors.lastname: Hack
authors.affiliation: Discovery Sciences, Janssen Research and Development, San Diego, California 92121.
authors.forename: Krystal
authors.initials: K
authors.lastname: Herman
authors.affiliation: From the Departments of Immunology and.
authors.forename: Leon
authors.initials: L
authors.lastname: Chang
authors.affiliation: From the Departments of Immunology and.
authors.forename: John M
authors.initials: JM
authors.lastname: Keith
authors.affiliation: Discovery Sciences, Janssen Research and Development, San Diego, California 92121.
authors.forename: Tara
authors.initials: T
authors.lastname: Mirzadegan
authors.affiliation: From the Departments of Immunology and.
authors.forename: Navin L
authors.initials: NL
authors.lastname: Rao
authors.affiliation: From the Departments of Immunology and.
authors.forename: Alec D
authors.initials: AD
authors.lastname: Lebsack
authors.affiliation: Discovery Sciences, Janssen Research and Development, San Diego, California 92121. Electronic address: mmilla@adaptivebiotech.com.
authors.forename: Marcos E
authors.initials: ME
authors.lastname: Milla
mesh_terms: D058946:5-Lipoxygenase-Activating Protein Inhibitors / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D058927:5-Lipoxygenase-Activating Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D000818:Animals; D001665:Binding Sites / Q000235:genetics; D055162:Biocatalysis / Q000187:drug effects; D018360:Crystallography, X-Ray; D004285:Dogs; D057075:Enzyme Assays / Q000379:methods; D006801:Humans; D007211:Indoles / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D051379:Mice; D008958:Models, Molecular; D015394:Molecular Structure; D009154:Mutation; D011485:Protein Binding; D000072417:Protein Domains; D011804:Quinolines / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D051381:Rats; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity
chemical_list: D058946:5-Lipoxygenase-Activating Protein Inhibitors; D058927:5-Lipoxygenase-Activating Proteins; D007211:Indoles; D011804:Quinolines; C078266:MK 0591
keywords: arachidonic acid (AA, ARA); computational biology; drug discovery; leukotriene; medicinal chemistry; membrane protein