50,00  excl. 19% VAT


Irreversible inhibitor of cysteine proteases


4096-v 0.5 mg 50.00 EUR



(M.W. 357.41) C15H27N5O5 [66701-25-5]


4096-25 25 mg 195.00 EUR
4096-100 100 mg 445.00 EUR


[(2S,3S)-3-carboxyoxirane-2-carbonyl]-L-Leucyl-4-(guanidobutyl)amide · ½H2O

(M.W. 357.41 · 9.01) C15H27N5O5 · ½H2O [66701-25-5]

Synthetic Product

E-64 is a very effective irreversible inhibitor of cysteine proteases and blocks specific thiol proteases like papain, cathepsin B and L, bromelain and ficin. It reacts with the active site of the enzyme in an equimolar manner by forming a thioether bond with the sulfhydryl group. E-64 did not react with cathepsin A and D and does not affect cysteine residues in several other enzymes. The effective concentration of E-64 is around 1-10 µM. Aliquots of E-64 in DMSO are stable at +4° over some days and can be stored in a freezer at -20°C for about one month. Solutions in water or water/ethanol are possible as well.
The inhibitor E-64 offered from Peptanova is of synthetic origin manufactured by Peptide Institute Inc. under strict quality control. Please keep in mind, that all products offered from PeptaNova or Peptide Institute Inc. are manufactured and certified as fine chemicals for laboratory use only. Our peptides are not manufactured under GMP and are not suitable for drug use, neither in humans nor in animals.

In addition to the commonly used inhibitor E-64 offers Peptanova two more E-64 derivatives: The membrane-impermeable calpain inhibitor E-64-d / 4621-v and 4320-v E-64-c which shows good membrane permeability.


  1. K. Hanada, M. Tamai, M. Yamagishi, S. Ohmura, J. Sawada and I. Tanaka, Agric. Biol. Chem., 42, 523 (1978) (Original)
  2. K. Hanada, M. Tamai, S. Ohmura, J. Sawada, T. Seki and I. Tanaka, Agric. Biol. Chem., 42, 529 (1978) (Structure & Chem. Synthesis)
  3. Y. Shoji-Kasai, M. Senshu, S. Iwashita and K. Imahori, Proc. Natl. Acad. Sci. USA, 85, 146 (1988) (Pharmacology of inhibior E-64)

For Laboratory use only! Not for Drug Use!