Leupeptin hemisulfate (103476-89-7) is a reversible inhibitor of trypsin-like proteases and cysteine proteases. Inhibits trypsin, plasmin, papain and cathepsin B, H and L.1-3Blocks various apoptotic pathways in T cells.4Commonly used in cell lysis buffers to protect proteins from degradation. Typical working concentration is 1μM (0.5 μg/ml).
White to off-white lyophilized powder
Leupeptin has been used as a protease inhibitor: in ice-cold lysis buffer to harvest cells for western immunoblotting and immunoprecipitation,in chromatin immunoprecipitation (ChIP) lysis buffer for the isolation of fragmented chromatin samples in lysis buffer I to lyse the cells for tandem affinity purification (TAP)
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.
Reversible protease inhibitor, which inhibits cathepsin B, calpain and trypsinPharmaceutical composition containing leupeptin hemisulfate is used as an anti-malarial agent. It is employed in the treatment of noise-induced hearing loss. It also protects the heart from myocardial stunning. Further, it is used to inhibit serine, cysteine proteases, plasmin, trypsin, papain, kallikrein and cathepsin B.
ChEBI: A peptide sulfate salt obtained by combining leupeptin with 0.5 molar equivalents of sulfuric acid.
Leupeptin, or
N-acetyl-L-leucyl-L-leucyl-L-argininal, is a naturally occurring tripeptide that acts particularly as a serine protease inhibitor and as a cysteine protease inhibitor. Its mechanism of action involves structurally similar covalent binding reactions:
- In the active site of serine proteases, leupeptin forms a covalent hemiacetal adduct between the aldehyde group of leupeptin and the hydroxyl group of a serine residue in the enzyme active site.
- In the active site of cysteine proteases, the electrophilic (aldehyde) carbon of leupeptin forms a comparable bond with the sulfur atom of a cysteine residue in the enzyme active site.
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.)
The peptide sulfate salt Leupeptin Hemisulfate is a serine and cysteine proteinase inhibitor that strongly blocks proteolysis by plasmin, trypsin, cathepsin B, and papain, but does not inhibit proteolysis by α-chymotrypsin or thrombin. Inhibition of the calcium-dependent protease calpain by Leupeptin Hemisulfate in murine cochlea explant cultures prevented hearing loss from aminoglycoside ototoxicity and neomycin-induced loss of outer hair cells. Leupeptin Hemisulfate inhibited calpain, rescued primary rat motoneurons exposed to α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid from cell death, and improved muscle function following nerve injury. Exposure of starved rats to Leupeptin Hemisulfate resulted in inhibition of lysosomal cysteine proteinases and blocked autolysosomal protein degradation, resulting in hepatic autolysosome accumulation. Leupeptin Hemisulfate is one of several inhibitors of cathepsin L, a cysteine protease that can cleave and activate the severe acute respiratory syndrome coronavirus-2 spike protein. Leupeptin Hemisulfate treatment of HuH-7 cells inhibited infection by live SARS-CoV-2 virus in vitro.
[1] T AOYAGI. Leupeptins, new protease inhibitors from Actinomycetes.[J]. Journal of Antibiotics, 1969, 22 6: 283-286. DOI:
10.7164/antibiotics.22.283[2] A J BARRETT H K. Cathepsin B, Cathepsin H, and cathepsin L.[J]. Methods in enzymology, 1981, 80 Pt C: 535-561. DOI:
10.1016/s0076-6879(81)80043-2[3] KNIGHT C G. Human cathepsin B. Application of the substrate N-benzyloxycarbonyl-L-arginyl-L-arginine 2-naphthylamide to a study of the inhibition by leupeptin.[J]. Biochemical Journal, 1980, 189 3: 447-453. DOI:
10.1042/bj1890447[4] A SARIN P A H H Nakajima. A protease-dependent TCR-induced death pathway in mature lymphocytes.[J]. Journal of immunology, 1995, 154 11: 5806-5812.
