Leupeptin

Protease Inhibitor Peptide AldehydeRx: ResearchCompound: Research

Also known as: Ac-Leu-Leu-Arg-al, Acetyl-leupeptin, Leupeptin hemisulfate, N-Acetyl-L-leucyl-L-leucyl-L-argininal

Educational Only — Not medical advice. Consult a qualified clinician before using any peptide.

Summary

Leupeptin is a naturally occurring tripeptide aldehyde (Ac-Leu-Leu-Arg-al) produced by Streptomyces species. It is a potent, reversible inhibitor of serine and cysteine proteases and is widely used as a research tool in cell biology and biochemistry to prevent proteolytic degradation in cell lysates and experimental assays. It has no approved clinical use.

Mechanism of Action

Reversible inhibitor of serine and cysteine proteases; acetylates the active site of target enzymes such as trypsin, plasmin, thrombin, papain, cathepsins, and calpains by forming a hemiacetal or thiohemiacetal with the catalytic serine or cysteine residue.

Routes of Administration

In VitroIntraperitoneal

Goals & Uses

  • Experimental neuroprotection modelPreclinical ResearchLow
  • Autophagy researchResearch ToolHigh
  • Cathepsin inhibitionResearch ToolHigh
  • Calpain inhibitionResearch ToolHigh
  • Protease inhibition in cell lysatesResearch/biochemistryHigh

Contraindications

  • Human therapeutic useRegulatory/safetyHigh

Adverse Effects

  • Cytotoxicity at high concentrationsIn Vitro ToxicityUncommon
  • Non-specific protease inhibitionOff Target EffectCommon

Drug Interactions

  • E-64 / E64dLow
  • PMSF (phenylmethylsulfonyl fluoride)Low

Population Constraints

  • All human populationsGeneralAbsolute

Regulatory Status

  • European UnionUnapprovedNo EMA approval; available only as a research chemical.
  • United StatesUnapprovedResearch reagent only; no FDA approval or IND filing on record.
  • United KingdomUnapprovedNo MHRA approval; research use only.

Not approved for human therapeutic use in any jurisdiction. Sold exclusively as a research-grade reagent. No IND or clinical trials on record for therapeutic application.

Evidence & Sources

No sources recorded yet.