title: Protein cargo delivery properties of cell-penetrating peptides. A comparative study.
abstract: 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.
authors.affiliation: Estonian Biocentre, 23 Riia Street, 51010 Tartu, Estonia.
authors.forename: Pille
authors.initials: P
authors.lastname: Säälik
authors.forename: Anna
authors.initials: A
authors.lastname: Elmquist
authors.forename: Mats
authors.initials: M
authors.lastname: Hansen
authors.forename: Kärt
authors.initials: K
authors.lastname: Padari
authors.forename: Külliki
authors.initials: K
authors.lastname: Saar
authors.forename: Kaido
authors.initials: K
authors.lastname: Viht
authors.forename: Ulo
authors.initials: U
authors.lastname: Langel
authors.forename: Margus
authors.initials: M
authors.lastname: Pooga
mesh_terms: D000595:Amino Acid Sequence; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism*; D002463:Cell Membrane Permeability / Q000235:genetics; D057846:Cell-Penetrating Peptides; D016503:Drug Delivery Systems / Q000379:methods*; D019004:Galanin; D015696:Gene Products, tat / Q000235:genetics / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000235:genetics / Q000378:metabolism*; D010455:Peptides / Q000235:genetics / Q000378:metabolism; D021381:Protein Transport / Q000235:genetics; D011506:Proteins / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D014862:Wasp Venoms
chemical_list: D002352:Carrier Proteins; D057846:Cell-Penetrating Peptides; D015696:Gene Products, tat; D010446:Peptide Fragments; D010455:Peptides; D011506:Proteins; D011993:Recombinant Fusion Proteins; D014862:Wasp Venoms; C437783:pVEC peptide; C110068:transportan; D019004:Galanin; C414409:penetratin