Improvement of porphyrin cellular delivery and activity by conjugation to a carrier peptide

Bioconjug Chem. Sep-Oct 2001;12(5):691-700. doi: 10.1021/bc000125t.


The chemical nuclease metalloporphyrin (manganese(III) porphyrin) can cleave DNA irreversibly and can thus constitute a potential antitumor drug. However, these molecules show low permeability to cell surface membranes. We report here the conjugation of an amphipathic carrier peptide to improve considerably its cellular delivery. The metalloporphyrin-peptide conjugate can be internalized by cells within only 5 min of incubation with a yield as high as 80%. Furthermore, the metalloporphyrin-peptide conjugate is able to cleave in vitro high or low molecular weight DNA to the same extend as metalloporphyrin alone without affecting the sequence-specific cleaving activity of the porphyrin. The conjugate is 100-fold more efficient at inducing tumor cells death than the free metalloporphyrin via a mechanism involving genomic DNA cleavage. The results are promising for further therapeutic applications with antitumor drugs such as metalloporphyrin, and also with other existing drugs by using a carrier peptide system in order to improve the cellular uptake of such molecules.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Antineoplastic Agents / chemistry
  • Antineoplastic Agents / pharmacokinetics*
  • Antineoplastic Agents / pharmacology
  • Binding Sites
  • Cell Division / drug effects
  • Cell Membrane Permeability / drug effects
  • DNA, Neoplasm / metabolism
  • Deoxyribonucleases / chemistry
  • Deoxyribonucleases / pharmacokinetics
  • Deoxyribonucleases / pharmacology
  • Drug Carriers / chemistry
  • Drug Carriers / pharmacokinetics
  • Humans
  • Metalloporphyrins / chemistry
  • Metalloporphyrins / pharmacokinetics*
  • Metalloporphyrins / pharmacology
  • Mice
  • Molecular Sequence Data
  • Peptides / chemistry
  • Peptides / pharmacokinetics*
  • Substrate Specificity
  • Surface-Active Agents / chemistry
  • Surface-Active Agents / pharmacokinetics
  • Tumor Cells, Cultured / drug effects


  • Antineoplastic Agents
  • DNA, Neoplasm
  • Drug Carriers
  • Metalloporphyrins
  • Peptides
  • Surface-Active Agents
  • manganese(III) porphyrin
  • Deoxyribonucleases