4RUT

crystal structure of murine cyclooxygenase-2 with 13-methyl-arachidonic Acid

Summary for 4RUT

• Entry DOI: 10.2210/pdb4rut/pdb
• Descriptor: Prostaglandin G/H synthase 2, 2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose, 2-acetamido-2-deoxy-beta-D-glucopyranose, ... (7 entities in total)
• Functional Keywords: protein-ligand complex, prostaglandin-endoperoxide synthase, fatty acid analog, oxidoreductase, glycosylation, membrane
• Biological source: Mus musculus (mouse)
• Total number of polymer chains: 4
• Total formula weight: 277135.12

Authors

Xu, S.,Kudalkar, S.N.,Banerjee, S.,Makriyannis, A.,Nikas, S.P.,Marnett, L.J. (deposition date: 2014-11-21, release date: 2015-02-11, Last modification date: 2023-09-20)

Primary citation

Kudalkar, S.N.,Nikas, S.P.,Kingsley, P.J.,Xu, S.,Galligan, J.J.,Rouzer, C.A.,Banerjee, S.,Ji, L.,Eno, M.R.,Makriyannis, A.,Marnett, L.J.
13-methylarachidonic Acid is a positive allosteric modulator of endocannabinoid oxygenation by cyclooxygenase.
J.Biol.Chem., 290:7897-7909, 2015

PubMed Abstract: Cyclooxygenase-2 (COX-2) oxygenates arachidonic acid (AA) and the endocannabinoids 2-arachidonoylglycerol (2-AG) and arachidonylethanolamide to prostaglandins, prostaglandin glyceryl esters, and prostaglandin ethanolamides, respectively. A structural homodimer, COX-2 acts as a conformational heterodimer with a catalytic and an allosteric monomer. Prior studies have demonstrated substrate-selective negative allosteric regulation of 2-AG oxygenation. Here we describe AM-8138 (13(S)-methylarachidonic acid), a substrate-selective allosteric potentiator that augments 2-AG oxygenation by up to 3.5-fold with no effect on AA oxygenation. In the crystal structure of an AM-8138·COX-2 complex, AM-8138 adopts a conformation similar to the unproductive conformation of AA in the substrate binding site. Kinetic analysis suggests that binding of AM-8138 to the allosteric monomer of COX-2 increases 2-AG oxygenation by increasing kcat and preventing inhibitory binding of 2-AG. AM-8138 restored the activity of COX-2 mutants that exhibited very poor 2-AG oxygenating activity and increased the activity of COX-1 toward 2-AG. Competition of AM-8138 for the allosteric site prevented the inhibition of COX-2-dependent 2-AG oxygenation by substrate-selective inhibitors and blocked the inhibition of AA or 2-AG oxygenation by nonselective time-dependent inhibitors. AM-8138 selectively enhanced 2-AG oxygenation in intact RAW264.7 macrophage-like cells. Thus, AM-8138 is an important new tool compound for the exploration of allosteric modulation of COX enzymes and their role in endocannabinoid metabolism.

PubMed: 25648895
DOI: 10.1074/jbc.M114.634014

Experimental method

X-RAY DIFFRACTION (2.16 Å)