Puijmbroeck_2026_Br.J.Pharmacol__

Covalent fluorescent probes have emerged as versatile chemical tools to visualise active enzymes in complex biological systems. When tailored for specific applications, ranging from activity-based protein profiling for drug development to high spatiotemporal resolution imaging of enzymatic activities, these probes provide unique insights into rapid lipid metabolism. The recent development of reverse-designing optimised inhibitors into probes, together with improved analytical techniques, is rapidly advancing our ability to resolve enzyme function in great detail. In this mini-review, we summarise the current landscape of covalent fluorescent probes for the 2-arachidonoylglycerol (2-AG) metabolising enzymes (diacylglycerol lipase, monoacylglycerol lipase, ABHD6 and ABHD12), highlighting the discoveries they have enabled and discussing strategies to address gaps where probes remain lacking.