Overview:

Leupeptin is a white or almost white powder. It is a trypsin inhibitor produced by Streptomyces roseus MB-26-AI, and is one of many protease inhibitors. Pure leupeptin has a melting point of 110-140℃, and is soluble in water, methanol, ethanol, butanol, and dimethyl sulfoxide, but insoluble in ethyl acetate, acetone, chloroform, hexane, etc. It reacts with Rydon-Smith and Sakaguchi, and shows positive reactions with ninhydrin, ferric chloride, anthrone, and Molli's. Leupeptin has an IC50 (half-inhibitory concentration) of 8μg/ml for plasmin, but does not inhibit chymotrypsin. Leupeptin can be directly dissolved in water as a protease inhibitor, with a solubility of 50mg/ml; a 10mM aqueous solution is stable for one week at 4℃ and for six months at -20℃; the working concentration is generally 10-100mM, and it is used on ice.

Purpose/Use

Lysostaphin is primarily used in biochemical research and can inhibit trypsin, papain, tissue proteinase B, plasmin, kallikrein, etc. Its inhibitory effect is competitive with the substrate. It can inhibit various serine and cysteine proteases.

Biological activity

Leupeptin Hemisulfate is a reversible inhibitor of lysosomal serine proteases and cysteine proteases. It inhibits cathepsin B (Ki=6 nM), calpain (Ki=10 nM), trypsin (Ki=35 nM), plasmin (Ki=3.4 μM), and kallikrein (Ki=19 μM), but has no effect on chymotrypsin, elastase, renin, or pepsin.

Target point

TargetValueCysteineproteaseserineprotease

In vitro study

Leupeptin, produced by various species of actinomycetes, strongly inhibits the hydrolysis of proteins. Leupeptin hemisulfate protects microtubule protein from degradation by endogenous proteolytic enzymes during the separation process, thereby enhancing the purity of microtubule protein. Leupeptin hemisulfate can restore up to 50% of the expression of hepatitis B surface antigen (HBsAg) in cell suspension culture medium.

In vivo study

Leupeptin(0-36mg/kg;intraperitonealinjection;for4hours;C57BL/6NCrlmalemice)iswelltoleratedbytheanimalsandproducesastrong,dose-dependentincreaseinLC3b-IIinboththetotaltissueextractsandthelysosomeandautophagosome-enrichedpelletfraction.AnimalModel:C57BL/6NCrlmalemice(6-8weeksold,20-25g)Dosage:0mg/kg,9mg/kg,18mg/kg,36mg/kgAdministration:Intraperitonealinjection;for4hoursResult:PromotedtheaccumulationofLC3b-IIinmouseliver.

Refer to quality standards

Appearance: white powder Purity (HPLC): ≥98.0%

Acetate content ≤12.0%

Moisture content ≤ 8.0%

Peptide content ≥ 80.0%

Endotoxin ≤ 50 EU/mg

Amino acid composition analysis: ≤±10%