1. Product Overview
Leupeptin, CAS 4578-31-8, also known as Acetyl-Leu-Leu-Arginal or LLRL, is a reversible competitive inhibitor of serine and cysteine proteases including trypsin chymotrypsin plasmin and cathepsins B and L. It is commonly supplied as the hemisulfate salt CAS 3733-88-8 which appears as a white to off white crystalline powder or as a white lyophilized cake in vials. The free base and salt are readily soluble in water giving a clear to slightly yellow solution pH around 5 to 6 which is unstable over time especially at room temperature. This product is provided in 98 percent or greater purity for biochemical and cell biology applications as a protease inhibitor added to cell lysis buffers tissue homogenates and Western blot sample preparations to prevent unwanted protein degradation.
2. Key Features & Advantages
• Broad spectrum reversible inhibition of serine proteases trypsin chymotrypsin and cysteine proteases cathepsin B L plasmin with low nanomolar IC50 values ensuring effective protection of target proteins during extraction.
• Supplied as lyophilized white powder or cake in amber or clear vials under inert gas for maximum stability and easy reconstitution in water or buffer.
• Hemisulfate salt form offers improved solid state stability compared to free base and is highly water soluble up to 10 to 50 mg per mL.
• Compatible with common lysis buffers RIPA PBS Tris based and with cocktail inhibitors such as aprotinin PMSF bestatin etc.
• Strictly for research use only in vitro not for therapeutic diagnostic or in vivo human animal use.
• Available in 98 percent HPLC grade and cell culture tested grades with low endotoxin options.
3. Main Applications
• Cell and molecular biology: added to cell lysis buffers tissue homogenates and nuclear extracts at 1 to 10 micromolar final concentration to inhibit endogenous proteases during protein extraction for SDS PAGE Western blotting co IP and mass spectrometry.
• Enzyme kinetics: used in vitro to study trypsin chymotrypsin plasmin and cathepsin activity by monitoring substrate cleavage in presence of leupeptin as competitive inhibitor.
• Tissue culture and ex vivo studies: low concentration supplementation in media to reduce extracellular proteolysis during primary cell or tissue slice cultures research only.
• Biochemistry: protecting labile proteins and peptides during purification from mammalian plant or microbial sources; also used in studying lysosomal enzyme functions.
• For research use only not for human or animal therapeutic diagnostic or clinical application.
4. Technical Specifications
5. Storage & Handling
• Packaging: laboratory 1 mg 5 mg 25 mg 100 mg in amber or clear glass vials with septa or screw caps often as white lyophilized cake or powder under argon or nitrogen; bulk 1 g in aluminum foil bag with desiccant; reconstitute with sterile water or buffer to 1 to 10 mg per mL stock aliquot and store frozen.
• Storage Conditions: store lyophilized solid at minus 20 degree C or minus 80 degree C protected from light and moisture preferably in a desiccator; highly unstable in solution at room temperature use immediately or keep on ice short term 4 C few hours; for longer keep aliquots at minus 20 C or minus 80 C and avoid repeated freeze thaw cycles.
• Shelf Life: 12 to 24 months unopened lyophilized powder stored at minus 20 C in dark; reconstituted solution stable a few hours on ice 4 C up to 1 week at minus 20 C aliquoted; discard if yellowing or precipitate appears.
• Handling: use in a biosafety cabinet or clean bench with gloves; avoid light heat and repeated thawing; wear nitrile gloves safety goggles and lab coat; prepare solutions with cold buffer and keep on ice.
6. Safety Overview
• GHS Classification: Warning GHS07; Acute Tox 4 Oral; Skin Irrit 2; Eye Irrit 2A; STOT SE 3 Respiratory irritation.
• Hazard Statements: H302 Harmful if swallowed; H315 Causes skin irritation; H319 Causes serious eye irritation; H335 May cause respiratory irritation.
• Protective Measures: wear nitrile gloves safety glasses and lab coat; handle in well ventilated clean area; protect from light; avoid generating dust or aerosol during weighing of powder.
• First Aid: Inhalation move to fresh air seek medical attention if irritation persists; Eye Contact rinse immediately with plenty running water min 15 minutes remove contact lenses get medical advice; Skin Contact wash with soap and water remove contaminated clothing; Ingestion rinse mouth do NOT induce vomiting drink small water seek immediate medical advice harmful if swallowed.
• Environmental Precautions: peptide based inhibitor may affect aquatic organisms at high concentration; do not discharge powder or solution into drains; collect as biochemical hazardous waste per local regs; for research only not for therapeutic use; not classified as DG general lab waste.
