Metal ions, such as Na+, Mg2+, Ca2+, and Zn2+, are highly abundant in biological systems. For many G protein‐coupled receptors (GPCRs), metal ions, especially Na+, have been found to stabilize the receptors' inactivate state preventing receptor activation. Besides this role, recent studies indicated that metal ions can modulate ligand–GPCR interactions allosterically. These findings on ion‐mediated GPCR signaling open new vistas for understanding the functioning of GPCRs and further could help in designing potent therapeutic compounds targeting GPCRs. Here we report on recent findings about role of orthosteric and allosteric metal ions in GPCR signaling and drug discovery. This article is categorized under: Structure and Mechanism > Molecular Structures Molecular and Statistical Mechanics > Molecular Mechanics Molecular and Statistical Mechanics > Molecular Interactions

Traditionally, it is believed that the substrate and products of a monoacylglycerol lipase (MGL) share the same path to enter and exit the catalytic site. Glycerol (a product of MGL), however, was recently hypothesized to be released through a different path. In order to improve the catalytic efficacy and thermo-stability of MGL, it is important to articulate the pathways of a MGL products releasing. In this study, with structure biological approaches, biochemical experiments, and in silico methods, we prove that glycerol is released from a different path in the catalytic site indeed. The fatty acid (another product of MGL) does share the same binding path with the substrate. This discovery paves a new road to design MGL inhibitors or optimize MGL catalytic efficacy.