title: Biochemical characterization and in vitro activity of AZ513, a noncovalent, reversible, and noncompetitive inhibitor of fatty acid amide hydrolase.
abstract: Fatty acid amide hydrolase (FAAH) hydrolyzes several bioactive lipids including the endocannabinoid anandamide. Synthetic FAAH inhibitors are being generated to help define the biological role(s) of this enzyme, the lipids it degrades in vivo, and the disease states that might benefit from its pharmacological modulation. AZ513 inhibits human FAAH (IC(50)=551 nM), is 20-fold more potent against rat FAAH (IC(50)=27 nM), and is inactive at 10 μM against the serine hydrolases acetylcholinesterase, thrombin, and trypsin. In contrast to most other potent FAAH inhibitors, AZ513 showed no evidence of covalently modifying the enzyme and displayed reversible inhibition. In an enzyme cross-competition assay, AZ513 did not compete with OL-135, an inhibitor that binds to the catalytic site in FAAH, which indicates that AZ513 does not bind to the catalytic site and is therefore noncompetitive with respect to substrate. AZ513 has good cell penetration as demonstrated by inhibition of anandamide hydrolysis in human FAAH-transfected HEK293 cells (IC(50)=360 nM). AZ513 was tested in a rat spinal cord slice preparation where CB(1) activation reduces excitatory post-synaptic currents (EPSCs). In this native tissue assay of synaptic activity, AZ513 reduced EPSCs, which is consistent with inhibiting endogenous FAAH and augmenting endocannabinoid tone. AZ513 has a unique biochemical profile compared with other published FAAH inhibitors and will be a useful tool compound to further explore the role of FAAH in various biological processes.
authors.affiliation: CNS Discovery Research, AstraZeneca Pharmaceuticals, 1800 Concord Pike, Wilmington, DE 19803, USA. clay.scott@astrazeneca.com
authors.forename: Clay W
authors.initials: CW
authors.lastname: Scott
authors.forename: Gaochao
authors.initials: G
authors.lastname: Tian
authors.forename: Xiao Hong
authors.initials: XH
authors.lastname: Yu
authors.forename: Kathy A
authors.initials: KA
authors.lastname: Paschetto
authors.forename: Dee E
authors.initials: DE
authors.lastname: Wilkins
authors.forename: Luc
authors.initials: L
authors.lastname: Meury
authors.forename: Chang Qing
authors.initials: CQ
authors.lastname: Cao
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Varnes
authors.forename: Philip D
authors.initials: PD
authors.lastname: Edwards
mesh_terms: D000581:Amidohydrolases / Q000037:antagonists & inhibitors*; D000818:Animals; D001549:Benzamides / Q000737:chemistry* / Q000494:pharmacology*; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D004791:Enzyme Inhibitors / Q000737:chemistry* / Q000494:pharmacology*; D057809:HEK293 Cells; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D018408:Patch-Clamp Techniques; D011743:Pyrimidines / Q000737:chemistry* / Q000494:pharmacology*; D011758:Pyrroles / Q000737:chemistry* / Q000494:pharmacology*; D051381:Rats; D013116:Spinal Cord / Q000187:drug effects / Q000502:physiology; D013569:Synapses / Q000187:drug effects; D000099252:Fatty Acid Amide Hydrolases
chemical_list: D000581:Amidohydrolases; D001549:Benzamides; D004791:Enzyme Inhibitors; D011743:Pyrimidines; D011758:Pyrroles; D000099252:Fatty Acid Amide Hydrolases; C568658:2,3-dichloro-N-(1H-pyrrolo(2,3-b)pyridin-5-yl)benzamide