L-Methionine-DL-sulfoximine

L-Methionine-DL-sulfoximine (CAS No.: 15985-39-4) is a synthetic sulfoximine derivative of L-methionine widely used as a highly specific and irreversible inhibitor of glutamine synthetase, a key enzyme responsible for the ATP-dependent conversion of glutamate to glutamine, thereby regulating nitrogen metabolism and neurotransmitter cycling. By covalently inactivating glutamine synthetase, this compound disrupts glutamine homeostasis and downstream metabolic pathways, leading to pronounced effects on astrocyte function, including alterations in cellular morphology and metabolic activity, and serving as a valuable tool to investigate glutamine-dependent mechanisms of ammonia-induced neuronal toxicity and neuroglial interactions. In vitro studies demonstrate that L-Methionine-DL-sulfoximine inhibits glutamine synthetase activity in the low micromolar range under specific preincubation conditions, with its efficacy influenced by substrate availability, and it has been shown to act as a potent convulsant in experimental models, reflecting its impact on excitatory neurotransmission. Beyond neuroscience, it is also employed in plant and microbial research, where it enhances the release of fixed nitrogen in cyanobacteria and provides insight into nitrogen assimilation pathways, supporting its relevance in agricultural and biofertilizer studies. This compound is commonly utilized in cell-based assays, isolated tissue systems, and in vivo models to probe metabolic regulation, enzyme inhibition, and neurotoxicity, with experimental concentrations or dosing regimens adjusted according to the specific biological context and study objectives.