Not available outside of the UK & Ireland.

Analysis Note

Leupeptin gives multiple peaks on HPLC due to equilibria among three forms in solution. Purity determined using three main peaks. Majority of contaminating peptide is racemized leupeptin.

Application

Leupeptin as well as other protease inhibitors like antipain, chymostatin, pepstatin, and phosphoramidon are useful for the protection of proteins during their isolation from tissues or membranes. Leupeptin can be removed from the reaction by dialysis.Note: To check other protease inhibitors, try our Protease Inhibitor Set including Antipain Dihydrochloride, Aprotinin, Bestatin, Chymostatin, E-64, EDTA-Na₂, Leupeptin, Pefabloc SC, Pepstatin, and Phosphoramidon.

Biochem/physiol Actions

Inhibitor of serine and cysteine proteases. Inhibits plasmin, trypsin, papain, calpain, and cathepsin B. Does not inhibit pepsin, cathepsins A and D, thrombin, or α-chymotrypsin. Effective concentration 10-100 µM. There have been numerous studies using leupeptin to protect against hearing loss caused by acoustic overstimulation or the ototoxic antibiotic gentamicin. (Loss of cochlear hair cells is believed to be mediated by calpain.)

Features and Benefits

ContentsSynthetic, white powder

Other Notes

For life science research only. Not for use in diagnostic procedures.

Preparation Note

Working concentration: 0.5 to 5 µg/ml (1 to 20 µM)Comparison of working concentrations of pefabloc with leupeptin and PMSF is in files.Working solution: Solvent is recommended in distilled water.Highly soluble in water (1 mg/ml), methanol, ethanol, acetic acid, dimethyl formamide and dimethyl sulfoxide.Poorly soluble in acetone, chloroform, ethyl ether and n-hexane.Storage conditions (working solution): -15 to -25 °CIn aqueous solution leupeptin is stable for 1 month at 2 to 8 °C or for at least 6 months at - 15 to -25 °C, stored under nitrogen. For best results, freeze the dissolved inhibitor in aliquots and avoid repeated thawing.

Quality

Function test: Performance controlled with trypsin.

Reconstitution

Highly soluble in water (1 mg/ml). Stable for at least one week at 2 to 8 °C and 6 months frozen in aliquots at -15 to -25 °C.

Specificity

Leupeptin inhibits serine and thiol proteases such as trypsin, plasmin, proteinase K, kallikrein, papain, thrombin, and cathepsin A and B.Not affected are α-, β-, γ- and δ- chymotrypsin, pepsin, cathepsin D, elastase, renin, and thermolysin.