Epoxysuccinyl peptide-derived cathepsin B inhibitors: modulating membrane permeability by conjugation with the C-terminal heptapeptide segment of penetratin

Biol Chem. 2002 May;383(5):849-52. doi: 10.1515/BC.2002.090.

Abstract

Besides its physiological role in lysosomal protein breakdown, extralysosomal cathepsin B has recently been implicated in apoptotic cell death. Highly specific irreversible cathepsin B inhibitors that are readily cell-permeant should be useful tools to elucidate the effects of cathepsin B in the cytosol. We have covalently functionalised the poorly cell-permeant epoxysuccinyl-based cathepsin B inhibitor [R-Gly-Gly-Leu-(2S,3S)-tEps-Leu-Pro-OH; R=OMe] with the C-terminal heptapeptide segment of penetratin (R=epsilonAhx-Arg-Arg-Nle-Lys-Trp-Lys-Lys-NH2). The high inhibitory potency and selectivity for cathepsin B versus cathepsin L of the parent compound was not affected by the conjugation with the penetratin heptapeptide. The conjugate was shown to efficiently penetrate into MCF-7 cells as an active inhibitor, thereby circumventing an intracellular activation step that is required by other inhibitors, such as the prodrug-like epoxysuccinyl peptides E64d and CA074Me.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Affinity Labels / chemical synthesis
  • Affinity Labels / chemistry
  • Amino Acid Sequence
  • Carrier Proteins / chemistry
  • Carrier Proteins / pharmacokinetics*
  • Carrier Proteins / pharmacology
  • Cathepsin B / antagonists & inhibitors*
  • Cathepsin B / metabolism
  • Cathepsin L
  • Cathepsins / antagonists & inhibitors*
  • Cell Membrane Permeability
  • Cell-Penetrating Peptides
  • Cysteine Endopeptidases
  • Cysteine Proteinase Inhibitors / chemistry
  • Cysteine Proteinase Inhibitors / pharmacokinetics*
  • Cysteine Proteinase Inhibitors / pharmacology
  • Humans
  • Kinetics
  • Mammary Neoplasms, Experimental / enzymology
  • Molecular Sequence Data
  • Oligopeptides / chemical synthesis
  • Oligopeptides / pharmacokinetics*
  • Oligopeptides / pharmacology
  • Peptide Fragments / chemistry
  • Peptide Fragments / pharmacokinetics
  • Peptide Fragments / pharmacology
  • Structure-Activity Relationship
  • Tumor Cells, Cultured / drug effects
  • Tumor Cells, Cultured / enzymology

Substances

  • Affinity Labels
  • Carrier Proteins
  • Cell-Penetrating Peptides
  • Cysteine Proteinase Inhibitors
  • Oligopeptides
  • Peptide Fragments
  • penetratin
  • Cathepsins
  • Cysteine Endopeptidases
  • Cathepsin B
  • CTSL protein, human
  • Cathepsin L