Lactacystin, 0.1 mg

A small molecule research reagent supplied by STEMCELL Technologies, this compound is a metabolite originally isolated from Streptomyces. It acts as an irreversible proteasome inhibitor that binds to the catalytic β-subunit, with an IC50 of 4.8 μM. The compound has been reported to induce neurite outgrowth in mouse neuroblastoma cells and apoptosis in human monoblast U937 cells. Injection into the substantia nigra of mice has been shown to produce Parkinson's-like symptoms, making it useful for modeling protein degradation defects in Parkinson's disease.

Identified by CAS Number 133343-34-7, the substance has a chemical formula of C15H24N2O7S and a molecular weight of 376.4 g/mol, with a reported purity of ≥ 98%. Its chemical name is 3S-hydroxy-2R-(1-hydroxy-2-methylpropyl)-4R-methyl-5-oxo-2-pyrrolidinecarboxylate-N-acetyl-L-cysteine. The product is supplied as a clear film and is stable for 12 months from the date of receipt when stored at -20°C, protected from prolonged light exposure and, for long-term storage, kept with a desiccant. Reported solubility values include ≤ 5.3 mM in PBS (pH 7.2), ≤ 50 mM in DMSO, and ≤ 2.6 mM in absolute ethanol.

According to the manufacturer's Safety Data Sheet, the substance is not classified as hazardous under the 2012 OSHA Hazard Communication Standard or the Globally Harmonized System. Stock solutions should be prepared fresh, with a final DMSO concentration kept below 0.1% when added to cell culture media to avoid potential toxicity. The product is intended for research use only.