View Featured Offers >>
Activators & Inhibitors
Chemical Modulators

E-64 #90267

Citations (0)
Chemical structure of E-64.

Product Usage Information

E-64 is supplied as a lyophilized powder. For a 15 mM stock, reconstitute 5 mg of powder in 0.93 mL of DMSO. Working concentrations and length of treatment can vary depending on the desired effect.


Store lyophilized at -20ºC, desiccated. In lyophilized form, the chemical is stable for 24 months. Once in solution, store at -20ºC and use within 1 month to prevent loss of potency. Aliquot to avoid multiple freeze/thaw cycles.

Product Description

Molecular Weight 357.4 g/mol
Purity >99%
Molecular Formula C15H27N5O5
CAS 66701-25-5
Solubility Soluble in 1:1 mixture of water or ethanol at 20 mg/mL.


The small-molecule E-64 is an anti-parasitic and anti-malarial agent that acts as an irreversible, non-selective inhibitor of cysteine proteases. E-64 binds and inhibits the cysteine proteases cathepsin K (IC50 = 1.4 nM), cathepsin S (IC50 = 4.1 nM), and cathepsin L (IC50 = 2.5 nM) in human osteoclast assays. E-64 also inhibits other proteases, including cathepsin B, cathepsin H, papain, and calpain (1,2). Exposure of filarial parasites to E-64 inhibited cathepsin B and resulted in decreased parasite motility and viability (3). E-64 effectively inhibited a SUMO-1-like cysteine protease from the African swine fever virus, resulting in impaired viral replication and a possible treatment for a viral disease that typically causes high mortality in domestic pigs (4). Inhibition of cathepsin B by E-64 in tumor cell lines reduced the invasive properties of the cells by 75% (5). E-64 treatment of ischemia-reperfusion rat kidneys blocked calpain activity and reduced several markers of renal dysfunction (6).

Limited Uses

Except as otherwise expressly agreed in a writing signed by a legally authorized representative of CST, the following terms apply to Products provided by CST, its affiliates or its distributors. Any Customer's terms and conditions that are in addition to, or different from, those contained herein, unless separately accepted in writing by a legally authorized representative of CST, are rejected and are of no force or effect.

Products are labeled with For Research Use Only or a similar labeling statement and have not been approved, cleared, or licensed by the FDA or other regulatory foreign or domestic entity, for any purpose. Customer shall not use any Product for any diagnostic or therapeutic purpose, or otherwise in any manner that conflicts with its labeling statement. Products sold or licensed by CST are provided for Customer as the end-user and solely for research and development uses. Any use of Product for diagnostic, prophylactic or therapeutic purposes, or any purchase of Product for resale (alone or as a component) or other commercial purpose, requires a separate license from CST. Customer shall (a) not sell, license, loan, donate or otherwise transfer or make available any Product to any third party, whether alone or in combination with other materials, or use the Products to manufacture any commercial products, (b) not copy, modify, reverse engineer, decompile, disassemble or otherwise attempt to discover the underlying structure or technology of the Products, or use the Products for the purpose of developing any products or services that would compete with CST products or services, (c) not alter or remove from the Products any trademarks, trade names, logos, patent or copyright notices or markings, (d) use the Products solely in accordance with CST Product Terms of Sale and any applicable documentation, and (e) comply with any license, terms of service or similar agreement with respect to any third party products or services used by Customer in connection with the Products.

For Research Use Only. Not for Use in Diagnostic Procedures.
Cell Signaling Technology is a trademark of Cell Signaling Technology, Inc.
All other trademarks are the property of their respective owners. Visit our Trademark Information page.
To Purchase # 90267
Cat. # Size Qty. Price
5 mg