摘要：SummaryGlycyrrhetinic acid (GA) is a natural product of licorice with mitochondria targeting properties and shows broad anticancer activities, but its targets and underlying mechanisms remain elusive. Here, we identified the mitochondrial enzyme serine hydroxymethyltransferase 2 (SHMT2) as a target of GA by using chemical proteomics. Binding to and inhibiting the activity of SHMT2 by GA were validatedin vitroandin vivo. Knockout of SHMT2 or inhibiting SHMT2 with GA restricts mitochondrial energy supplies by downregulating mitochondrial oxidative phosphorylation (OXPHOS) and fatty acid β-oxidation, and consequently suppresses cancer cell proliferation and tumor growth. Crystal structures of GA derivatives indicate that GA occupies SHMT2 folate-binding pocket and regulates SHMT2 activity. Modifications at GA carboxylic group with diamines significantly improved its anticancer potency, demonstrating GA as a decent structural template for SHMT2 inhibitor development.Graphical abstractDisplay OmittedHighlights•Mitochondrial protein SHMT2 is a critical target of GA•GA downregulates OXPHOS and FAO through targeting SHMT2•GA targets the folate-binding pocket of SHMT2 and competes with THF•Diamine modification at GA carboxylic group improves anticancer potencyBiochemistry; Natural product biochemistry; Omics; Proteomics
