L-Methionine sulfoximine has been used as a potent inhibitor of glutamine synthetase (GS) activity.
glutamine synthetase inhibitor, ornithine decarboxylase enhancer, convulsant
Methionine sulfoximine inhibits both glutamine synthetase and g-glutamylcysteine synthetase. Working concentrations for inhibition of g-glutamylcysteine synthetase are 0.2-2.0 mM (52% inhibition occured at 100 mM).
Methionine sulfoximine is also a toxic
ChEBI: L-methionine sulfoximine is a methionine sulfoximine in which the amino group has S-stereochemistry. It has a role as a geroprotector and an EC 6.3.1.2 (glutamate--ammonia ligase) inhibitor. It is a methionine sulfoximine, a L-methionine derivative and a non-proteinogenic L-alpha-amino acid. It is a tautomer of a L-methionine sulfoximine zwitterion.
As a potent inhibitor of glutamine synthetase activity (GS), this reagent has widely been used as a selection agent for plasmid integration in Chinese hamster ovary (CHO) and other mammalian cell lines. The growing demand for high yield cell banks for production of recombinant proteins for therapeutics has resulted in two major systems for selection of stable and active clones, Methotrexate selection of dihydrofolate reductase (DHFR) overexpressing cells and MSX selection of glutamine synthetase overexpressing cells. Cells are grown in the absence of glutamine in the media and inhibition of the endogenous activity of glutamine synthetase results in cell death for cells lacking overexpression. The MSX-glutamine synthetase selection mechanism provides benefits over that of the Methotrexate-DHFR system in that it typically requires a single amplification step and results in significant reduction of time to produce high stability, highly amplified clones. L-Methionine sulfoximine (MSX) enhances NH3 production in seedling leaves wheat, barley, corn and sorghum plants by inhibiting GS activity. MSX increases ornithine decarboxylase activity and decreases the survival rate in a model of transient cerebral ischemia.
