• CAS:133343-34-7
  • Formula:C15H24N2O7S
  • MW:376.4 Da
  • Appearance:Lyophilized or white crystalline solid
  • Purity:≥98%
Product Name Qty
100 ug
200 ug
1 mg


Lactacystin is a microbial metabolite of Streptomyces strains and acts as a cell permeable, specific, and irreversible inhibitor of 20S proteasome and lysosomal enzyme, Cathepsin A. It irreversibly binds to N-terminal threonine residue on active site of catalytic B subunit of 20S proteasome and therefore blocks proteolytic activity.

The metabolite blocks the cell cycle and induces neurite outgrowth in a murine neuroblastoma cell line, Neuro-2a. It inhibits cell cycle progression in both the G0/G1 and G2/M phases of the cell cycle. Treatment of Lactacystin in Neuro-2a cells displays bipolar morphology and becomes progressively more multipolar.

It has been reported that lactacystin induces apoptosis in human monoblastic U937, confirming DNA fragmentation.



• Proteasome inhibitor

• Study of neuritogenesis



• “Lactacystin, a novel microbial metabolite, induces neuritogenesis of neuroblastoma cells”

• “Lactacystin, Proteasome Function, and Cell Fate”

• “Lactacystin, a Specific Inhibitor of the Proteasome, Induces Apoptosis in Human Monoblast U937 Cells”


Not for human therapeutic use or for medicinal purposes. For research applications only.

More Information
Alternate Name/Synonyms
Chemical Name
(2R)-2-acetamido-3-[(2R,3S,4R)-3-hydroxy-2-[(1S)-1-hydroxy-2-methylpropyl]-4-methyl-5-oxopyrrolidine-2-carbonyl]sulfanylpropanoic acid
Chemical Formula
Molecular Weight
376.4 Da
Lyophilized or white crystalline solid
Soluble in DMSO, water or ethanol
Melting Point
236 – 238°C
Storage Temp
-20°C, desiccated, store up to 1 month.
Not Applicable
Lactacystin is a potent and selective irreversible proteasome inhibitor and cathepsin A inhibitor. Lactacystin is a microbial metabolite isolated from Streptomyces first characterized by its ability to induce differentiation and inhibit cell cycle progression in several tumor cell lines. Lactacystin irreversibly alkylates subunit X of the 20S proteasome. The concomitant inhibition of proteasome peptidase activity results in the accumulation of a variety of ubiquitinated proteins. Thus, the effects of this substance are pleiotropic and depend substantially on the expression pattern of signaling proteins within the treated cell. It is shown to inhibit cell proliferation and to induce neurite outgrowth in murine neuroblastoma cell lines such as Neuro 2a.
Keep container tightly closed in a dry and well-ventilated place. Provide appropriate exhaust ventilation at places where dust is formed.
MYELOID NEOPLASIA: Sphingosine kinase-1 and sphingosine 1-phosphate receptor 2 mediate Bcr-Abl1 stability and drug resistance by modulation of protein phosphatase 2A Arelis Salas, Suriyan Ponnusamy, Can E. Senkal, Marisa Meyers-Needham, Shanmugam Panneer Selvam, Sahar A. Saddoughi, Elif Apohan, R. David Sentelle, Charles Smith, Christopher R. Gault, Lina M. Obeid, Hesham M. El-Shewy, Joshua Oaks, Ramasamy Santhanam, Guido Marcucci, Yusuf Baran, Sandeep Mahajan, Daniel Fernandes, Robert Stuart, Danilo Perrotti, and Besim Ogretmen Blood, Jun 2011; 117: 5941 - 5952.
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HandlingKeep container tightly closed in a dry and well-ventilated place. Provide appropriate exhaust ventilation at places where dust is formed.
CitationsLactacystin exhibits potent anti-tumor activity in an animal model of malignant glioma when administered via controlled-release polymers
Prolyl oligopeptidase inhibition attenuates the toxicity of a proteasomal inhibitor, lactacystin, in the alpha-synuclein overexpressing cell culture
Sphingosine kinase-1 and sphingosine 1-phosphate receptor 2 mediate Bcr-Abl1 stability and drug resistance by modulation of protein phosphatase 2A
Notch1 modulates timing of G1-S progression by inducing SKP2 transcription and p27 Kip1 degradation
Inflammatory cytokines induce phosphorylation and ubiquitination of prostate suppressor protein NKX3.1
Bortezomib blocks the catabolic process of autophagy via a cathepsin-dependent mechanism, affects endoplasmic reticulum stress and induces caspase-dependent cell death in antiestrogen-sensitive and resistant ER+ breast cancer cells
Bortezomib blocks the catabolic process of autophagy via a cathepsin-dependent mechanism, affects endoplasmic reticulum stress, and induces caspase-dependent cell death in antiestrogen–sensitive and resistant ER+ breast cancer cells
Chloroquine promotes apoptosis in melanoma cells by inhibiting BH3 domain-mediated PUMA degradation
GDNF Overexpression from the Native Locus Reveals its Role in the Nigrostriatal Dopaminergic System Function
Prevention and restoration of lactacystin-induced nigrostriatal dopamine neuron degeneration by novel brain-permeable iron chelators
Reduced cellular expression and activity of the P129T mutant of human fatty acid amide hydrolase: evidence for a link between defects in the endocannabinoid system and problem drug use
Genetic iron chelation protects against proteasome inhibition-induced dopamine neuron degeneration
Soluble HIV Tat protein removes the IL-7 receptor alpha-chain from the surface of resting CD8 T cells and targets it for degradation
Dendritic cells use endocytic pathway for cross-priming class Ib MHC-restricted CD8alphaalpha+TCRalphabeta+ T cells with regulatory properties
Involvement of secretory and endosomal compartments in presentation of an exogenous self-glycolipid to type II NKT cells
Parkin is recruited to the centrosome in response to inhibition of proteasomes
Pirh2 E3 ubiquitin ligase targets DNA polymerase eta for 20S proteasomal degradation
Degradation of Redox-Sensitive Proteins including Peroxiredoxins and DJ-1 is Promoted by Oxidation-induced Conformational Changes and Ubiquitination
TAp73 protein stability is controlled by histone deacetylase 1 via regulation of Hsp90 chaperone function
A protease pathway for the repair of topoisomerase II-DNA covalent complexes
Proteasome mediates dopaminergic neuronal degeneration, and its inhibition causes alpha-synuclein inclusions
Comparison of neuroprotective and neurorestorative capabilities of rasagiline and selegiline against lactacystin-induced nigrostriatal dopaminergic degeneration
The COOH terminus of megalin regulates gene expression in opossum kidney proximal tubule cells
Chlamydial effector proteins localized to the host cell cytoplasmic compartment
Modulation of osteoblast gap junction connectivity by serum, TNFalpha, and TRAIL
Differential effects of lactacystin on cytokine production in activated Jurkat cells and murine splenocytes
Delta-catenin/NPRAP: A new member of the glycogen synthase kinase-3beta signaling complex that promotes beta-catenin turnover in neurons
Neuroprotection by iron chelator against proteasome inhibitor-induced nigral degeneration
Proteasome inhibitors mechanism; source for design of newer therapeutic agents
Inhibition of the ubiquitin-proteasome system sensitizes TRAIL-resistant prostate cancer cells by up-regulation of death receptor 5
A critical role for the inducible proteasomal subunits LMP7 and MECL1 in cytokine production by activated murine splenocytes
Photic regulation of melatonin in rat retina and the role of proteasomal proteolysis
Functional 20S proteasomes in mature human red blood cells
HIV-1 Tat protein down regulates interleukin-7 receptor alpha on CD8 T cells
Inflammatory Cytokines Induce Ubiquitination and Loss of the Prostate Suppressor Protein NKX3. 1
The effects of tumor necrosis factor-alpha (TNF-α) on tight junction proteins of the brain endothelial cells
The antiepidermal growth factor receptor monoclonal antibody cetuximab/C225 reduces hypoxia-inducible factor-1 alpha, leading to transcriptional inhibition of vascular endothelial growth factor expression
Neuroprotection of rapamycin in lactacystin-induced neurodegeneration via autophagy enhancement
Combination of proteasomal inhibitors lactacystin and MG132 induced synergistic apoptosis in prostate cancer cells
Oxidative Stress Modulates the Expression Pattern of Peroxiredoxin-6 in Peripheral Blood Mononuclear Cells of Asthmatic Patients and Bronchial Epithelial Cells
The effect of prolyl oligopeptidase inhibitors on alpha-synuclein aggregation and autophagy cannot be predicted by their inhibitory efficacy
RING-finger protein 166 plays a novel pro-apoptotic role in neurotoxin-induced neurodegeneration via ubiquitination of XIAP
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