Protein cargo delivery properties of cell-penetrating peptides. A comparative study

Bioconjug Chem. 2004 Nov-Dec;15(6):1246-53. doi: 10.1021/bc049938y.


Application of cell-penetrating peptides for delivering various hydrophilic macromolecules with biological function into cells has gained much attention in recent years. We compared the protein transduction efficiency of four cell-penetrating peptides: penetratin, Tat peptide, transportan, and pVEC and studied the effects of various medium parameters on the uptake. Depletion of cellular energy and lowering of temperature strongly impaired the internalization of protein complexed with cell-penetrating peptides, confirming the endocytotic mechanism of peptide-mediated protein cellular transduction. Peptide-induced protein association with HeLa cells decreased 3-6-fold in energy-depleted cells. Inhibition of clathrin-dependent endocytosis by the hyperosmolar medium decreased the uptake of peptide-avidin complexes 1.5-3-fold and the removal of cholesterol from the plasma membrane 1.2-2-fold, suggesting that both clathrin-dependent and independent endocytosis were involved in peptide-induced cellular delivery of avidin. However, even under conditions of cellular energy depletion, ceasing of cellular traffic, and partial depolarization of plasma membrane, peptide-protein complexes associated with HeLa cells, as observed by FACS analysis and spectrofluorimetry. Among the studied peptides, pTat and transportan revealed higher protein transduction efficiency than penetratin or pVEC.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism
  • Cell Membrane / metabolism*
  • Cell Membrane Permeability* / genetics
  • Cell-Penetrating Peptides
  • Drug Delivery Systems / methods*
  • Galanin
  • Gene Products, tat / genetics
  • Gene Products, tat / metabolism
  • HeLa Cells
  • Humans
  • Molecular Sequence Data
  • Peptide Fragments / genetics
  • Peptide Fragments / metabolism*
  • Peptides / genetics
  • Peptides / metabolism
  • Protein Transport / genetics
  • Proteins / genetics
  • Proteins / metabolism*
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Wasp Venoms


  • Carrier Proteins
  • Cell-Penetrating Peptides
  • Gene Products, tat
  • Peptide Fragments
  • Peptides
  • Proteins
  • Recombinant Fusion Proteins
  • Wasp Venoms
  • pVEC peptide
  • transportan
  • Galanin
  • penetratin