Assay of Monoacylglycerol Lipase Activity
Monoacylglycerol lipase (MGL) is a serine hydrolase involved in the biological deactivation of the endocannabinoid 2-arachidonoyl-sn-glycerol (2-AG). 2-AG is one of the main endogenous lipid agonists for cannabinoid receptors in the brain and elsewhere in the body. In the central nervous system (CNS), MGL is localized to presynaptic nerve terminals of both excitatory and inhibitory synapses, where it helps control the regulatory actions of 2-AG on synaptic transmission and plasticity. In this chapter, we describe an in vitro method to assess MGL activity by liquid chromatography/mass spectrometry (LC/MS)-based quantitation of the reaction product. This method may be used to determine the basal or altered MGL activity in various cells or animal tissues after pharmacological, genetic, or biological manipulations. In addition, this assay can be used for MGL inhibitor screening using purified recombinant enzyme or MGL-overexpressing cells.
Key wordsMonoacylglycerol lipase (MGL) Enzyme assay 2-Arachidonoyl-sn-glycerol (2-AG) Arachidonic acid Liquid chromatography/mass spectrometry (LC/MS)
This work was supported by grants DA012413 and DA031387 from NIDA (to D.P.). The contribution of the Agilent Technologies/University of California, Irvine Analytical Discovery Facility, is gratefully acknowledged. We thank Dr. Collin Merrill for critical reading of the manuscript and Jennifer Daglian for technical assistance.