Structure of Human N -Acylphosphatidylethanolamine-Hydrolyzing Phospholipase D: Regulation of Fatty Acid Ethanolamide Biosynthesis by Bile Acids

Abstract

SUMMARY The fatty-acid ethanolamides (FAEs) are lipid mediators present in all organisms and involved in highly conserved biological functions such as innate immunity, energy balance and stress control. They are produced from membrane N-acylphosphatidylethanolamines (NAPEs) and include agonists for G protein-coupled receptors (e.g. cannabinoid receptors) and nuclear receptors (e.g. PPAR-α). Here we report the crystal structure of human NAPE-hydrolyzing phospholipase D (NAPE-PLD) at 2.65 Å resolution, a membrane enzyme that catalyzes FAE formation in mammals. NAPE-PLD forms homodimers partly separated by an internal ~9 Å-wide channel and uniquely adapted to associate with phospholipids. A hydrophobic cavity provides an entryway for NAPE into the active site, where a binuclear Zn2+ center orchestrates its hydrolysis. Bile acids bind with high affinity to selective pockets in this cavity, enhancing dimer assembly and enabling catalysis. These elements offer multiple targets for the design of small-molecule NAPE-PLD modulators with potential applications in inflammation and metabolic disorders.

An Important Role for N-Acylethanolamine Acid Amidase in the Complete Freunds Adjuvant Rat Model of Arthritis

“…First, an N-acyltransferase activity, which remains to be molecularly cloned, transfers the palmitic or oleic acid chain from the sn-1 position of phosphatidylcholine to the amino group of phosphatidylethanolamine (PE). The newly formed N-acyl-PE is hydrolyzed to PEA and OEA by a selective phospholipase D, whose primary sequence and tridimensional structure have been elucidated (Okamoto et al, 2004;Wang et al, 2006;Magotti et al, 2015). Two distinct enzymes, fatty acid amide hydrolase and NAAA, are able to catalyze the hydrolysis of PEA and OEA into their constituent fatty acids and ethanolamine.…”

A Double Whammy: Targeting Both Fatty Acid Amide Hydrolase (FAAH) and Cyclooxygenase (COX) To Treat Pain and Inflammation

“…Therefore, the signaling activity of these substances is strictly dependent on the enzymes responsible for their formation and degradation. [6d, 7] FAAH is the main enzyme involved in the degradative hydrolysis of anandamide into arachidonic acid (AA) and ethanolamine (Figure 2). [8] It is a membrane-bound serine hydrolase localised to intracellular organelles such as microsomes and mitochondria, and is highly expressed in brain and liver, among other tissues.…”

Synthesis and characterization of the first inhibitor ofN-acylphosphatidylethanolamine phospholipase D (NAPE-PLD)

“…2–4 The FAEs are structurally and functionally diverse lipid mediators that act as agonists for G protein-coupled receptors (e. g., cannabinoid receptors), 6 ligand-activated transcription factors (e. g., peroxisome proliferator-activated receptor-α) 8 and ion channels (e. g., transient receptor potential subfamily V member 1, TRPV1). 9 The NAPEs, on the other hand, though traditionally viewed only as precursors for the FAEs, 10 are emerging as important regulators of key dynamic properties of the lipid bilayer – including stability 11–13 and fusogenicity 14,15 – and its interactions with intracellular signaling proteins.…”