Diacylglycerol lipases (DAGL) produce the endocannabinoid 2-arachidonoylglycerol, a key modulator of neurotransmitter release. Chemical tools that visualize endogenous DAGL activity are desired.... Show moreDiacylglycerol lipases (DAGL) produce the endocannabinoid 2-arachidonoylglycerol, a key modulator of neurotransmitter release. Chemical tools that visualize endogenous DAGL activity are desired. Here, we report the design, synthesis and application of a triazole urea probe for DAGL equipped with a norbornene as a biorthogonal handle. The activity and selectivity of the probe was assessed with activity-based protein profiling. This probe was potent against endogenous DAGLα (IC50 = 5 nM) and it was successfully applied as a two-step activity-based probe for labeling of DAGLα using an inverse electron-demand Diels–Alder ligation in living cells. Show less
Rooden, E.J. van; Kohsiek, M.J.J.; Kreekel, R.; Esbroeck, A.C.M. van; Nieuwendijk, A.M.C.H. van den; Janssen, A.P.A.; ... ; Stelt, M. van der 2018
Diacylglycerol lipases (DAGL) are responsible for the biosynthesis of the endocannabinoid 2‐arachidonoylglycerol. The fluorescent activity‐based probes DH379 and HT‐01 have been previously shown to... Show moreDiacylglycerol lipases (DAGL) are responsible for the biosynthesis of the endocannabinoid 2‐arachidonoylglycerol. The fluorescent activity‐based probes DH379 and HT‐01 have been previously shown to label DAGLs and to cross‐react with the serine hydrolase ABHD6. Here, we report the synthesis and characterization of two new quenched activity‐based probes 1 and 2, the design of which was based on the structures of DH379 and HT‐01, respectively. Probe 1 contains a BODIPY‐FL and a 2,4‐dinitroaniline moiety as a fluorophore–quencher pair, whereas probe 2 employs a Cy5‐fluorophore and a cAB40‐quencher. The fluorescence of both probes was quenched with relative quantum yields of 0.34 and 0.0081, respectively. The probes showed target inhibition as characterized in activity‐based protein profiling assays using human cell‐ and mouse brain lysates, but were unfortunately not active in living cells, presumably due to limited cell permeability. Show less
