Membrane phospholipid bilayer as a determinant of monoacylglycerol lipase kinetic profile and conformational repertoire

摘要: The membrane-associated serine hydrolase, monoacylglycerol lipase (MGL), is a well-recognized therapeutic target that regulates endocannabinoid signaling. Crystallographic studies, while providing structural information about static MGL states, offer no direct experimental insight into the impact of MGL's membrane association upon its structure–function landscape. We report application phospholipid bilayer nanodiscs as biomembrane models with which to evaluate effect system on catalytic properties and conformational dynamics human (hMGL). Anionic charge-neutral enhanced hMGL's kinetic [apparent maximum velocity (Vmax) substrate affinity (Km)]. Hydrogen exchange mass spectrometry (HX MS) was used analysis method profile experimentally extent hMGL–nanodisc interaction hMGL structure. provide evidence significant regions lid-domain helix α4 neighboring α6 interact nanodisc bilayer, anchoring in more open conformation facilitate ligand access enzyme's substrate-binding channel. Covalent modification by irreversible carbamate inhibitor, AM6580, shielded active site region, but did not increase solvent exposure lid domain, suggesting inactive, carbamylated enzyme remains intact associated. Molecular simulations generated congruent open, topology inhibited, covalently-modified hMGL. Our data indicate induces regional changes favor recruiting lipophilic substrate/inhibitor from stores via lid, resulting activity affinity.