lactacystin

**Lactacystin** is a naturally occurring metabolic product of *Streptomyces* species, first identified in 1991. It is a cell-permeable, potent, and irreversible **proteasome inhibitor** with high selectivity for the 20S proteasome. Lactacystin acts by covalently binding to the N-terminal threonine residue of β-subunits of the proteasome, thereby inhibiting its chymotrypsin-like, trypsin-like, and caspase-like peptidase activities. Its active transformation product, clasto-lactacystin β-lactone (also known as omuralide), mediates this covalent modification. Lactacystin is extensively used as a biochemical research tool for studies on proteasome function, protein degradation, and cell cycle regulation. It is not approved for therapeutic use in humans. There is interest in its potential as an anticancer agent and as a model for neurodegenerative disease research[1][3][4][7][9][10].

Other names

133343-34-7CHEBI:52722N-acetyl-S-({(2R,3S,4R)-3-hydroxy-2-[(1S)-1-hydroxy-2-methylpropyl]-4-methyl-5-oxopyrrolidin-2-yl}carbonyl)-L-cysteine(2R)-2-acetamido-3-[(2R,3S,4R)-3-hydroxy-2-[(1S)-1-hydroxy-2-methylpropyl]-4-methyl-5-oxopyrrolidine-2-carbonyl]sulfanylpropanoic acid