Synonyms: E-64; n-[n-( l-transepoxysuccinic acid)-l-leucyl]-agmatine; n-[n-(l-3-trans-carboxirane-2-carbonyl)-l-leucyl]-4-aminobutylguanidine; n-[n-(l-3-trans-carboxirane-2-carbonyl)-l-leucyl]-agmatine.
note: another name for l-3-trans-carboxyoxiran-2-carboxylic acid acid is l-transepoxysuccinic acid. agmatine is 4-aminobutylguanidine.; trans-Epoxysuccinyl-L-leucylamido(4-guanidino)butane; L-trans-3-Carboxyoxiran-2-carbonyl-L-leucylagmatine; N-(trans-Epoxysuccinyl)-L-leucine 4-guanidinobutylamide
Empirical Formula (Hill Notation): C15H27N5O5
Formula Weight: 357.41
Linear Formula: C15H27N5O5
MDL Number: MFCD00080261
Purity: >95% (HPLC)
Storage: 2-8°C
Beilstein Registry Number: 1405664
UNSPSC Code: 12352200
RIDADR: NONH for all modes of transport
Application:
E-64 is an effective ligand for affinity purification of cysteine proteases. When coupled to a thiolated affinity matrix, binding is no longer irreversible, but specificity is retained.
Biochem/physiol Actions:
E-64 is an irreversible, potent, and highly selective cysteine protease inhibitor. E-64 does not react with the functional thiol group of non-protease enzymes, such as L-lactate dehydrogenase or creatine kinase. E-64 will not inhibit serine proteases (except trypsin) like other cysteine protease inhibitors, leupeptin and antipain. The trans-epoxysuccinyl group (active moiety) of E-64 irreversibly binds to an active thiol group in many cysteine proteases, such as papain, actinidase, and cathepsins B, H, and L to form a thioether linkage. E-64 is a very useful cysteine protease inhibitor for use in in vivo studies because it has a specific inhibition, it is permeable in cells and tissues and has low toxicity.
Other Notes:
For life science research only. Not for use in diagnostic procedures.
Preparation Note:
E-64 is soluble in water. A 20 mg/ml solution can be prepared in water (heat may be needed). A suggested stock solution is a 1 mM aqueous solution. The effective concentration for use as a protease inhibitor is 1 to10 μM. Aqueous stock solutions are stable for months at -20 °C. Diluted solutions are stable for days at neutral pH. E-64 is stable from pH 2-10, but is unstable in ammonia or in HCl. E-64 is also soluble in DMSO, a 10 mM solution can be prepared in dry DMSO and stored at -20 °C. Subsequent dilutions were in culture medium. Solutions for injection were prepared by dissolving E-64 in 0.9% sodium chloride or in a minimum amount of saturated sodium bicarbonate followed by dilution with 0.9% sodium chloride (after adjusting the pH to 7.0 with acetic acid).
Reconstitution:
Soluble to 20 mg/ml in a 1:1 (v/v) mixture of ethanol and water. Solutions are stable for one month when stored in aliquots at -15 to -25 °C.
Specificity:
The thiol protease inhibitor E-64 specifically inhibits papain and other cysteine proteases such as cathepsin B and L, bromelain, and ficin. Cathepsin A and D are not inhibited. L-lactate dehydrogenase from porcine heart is not inhibited, although the enzyme contains a functional thiol group.