Cationic Cell Penetrating Peptides


Austin Biochem. 2016; 1(1): 1004.

Cationic Cell Penetrating Peptides

Jing Ye*

Department of Chemistry, Salem College, USA

*Corresponding author: Jing Ye, Department of Chemistry, Salem College, 601 S Church St, Winston- Salem, NC, 27101, USA

Received: October 28, 2016; Accepted: November 10, 2016; Published: November 14, 2016


Cell Penetrating Peptides (CPPs) or membrane transduction peptides are named for their ability to penetrate various types of cells [1,2]. They are synthetic peptides typically less than 30 amino acids in length. Their primary sequences come either from a parent protein expressed in cells or are derived from natural peptides [3- 11]. CPPs can carry cargos ranging from small molecules to macro molecules such as proteins and nucleic acids [12,13], which are otherwise difficult to translocate into cells. For this reason, they were quickly earmarked as potential cellular delivery tools. Understanding the mechanism of CPP cell entry is of great significance in both cell biology and targeted drug delivery.

The mechanisms, through which the CPPs translocated into cells, have been studied but are inconclusive. Some evidence indicates receptor independent endocytosis as the CPP cell entry mechanism [14-18]. The CPP endosomal release is considered as the main obstacle for the application of CPPs in drug delivery. Other evidence supports direct translocation through the cell membranes or nonendocytic pathways [19-22]. Still other studies have suggested that both endocytosis and direct translocation coexist for the CPPs’ cell entry [23-25]. The relative importance of the endocytosis and non-endocytosis mechanisms seems to depend on the extracellular concentration, the peptide sequence, and the cell types. The increasing concentration of the peptides increases the likely importance of nonendocytic translocation mechanisms.

CPPs could be hydrophobic, amphipathic, or hydrophilic. Although they lack a definite pattern for their primary sequences, the majority of CPPs are cationic being rich in basic amino acids such as arginine and lysine. They are, therefore, attracted to the partially negatively charged cell membranes [26] and proteoglycans on cell surfaces [27]. Cationic polypeptides, such as poly-lysine, Kn, and poly-arginine, Rn, were found to increase the serum albumin uptake in cells [28]. The fact that Rn has been shown to be more efficient at translocating into cells than Kn led to the belief that the guanidino group in arginine is crucial for cellular uptake of CPPs [26-30]. On the other hand, peptides such as Transportan, Hel 11-7, MAP, and MPG-a contain only lysine as their basic amino acids [31-34]. Therefore, it appears that the guanidino group though beneficial, is not required for CPP penetration. It is necessary to investigate the roles of the secondary structures of CPPs in their translocation across the cell membrane. For example, Penetratin and Transportan have adopted more a-helix in the presence of 2,2,2-trifluoroethanol (TFE) than in aqueous solutions [22]. TFE which provides a low dielectric constant similar to that of the cell membrane, favours the formation of intra-peptide hydrogen bonds [35]. My previous study of Penetratin in live melanoma cells revealed that the peptide contained both random coil and β-stand in the cytoplasm, and possibly assembled as β-sheets in the nucleus. Furthermore, evaluation of Rn, where n is between 6 to 30, for their cellular uptake showed the cell penetrating capacity peaked at R15 [29]. With the high structural flexibility and the short length, lysine and arginine rich CPPs have demonstrated the potential to adjust their conformation that may assist them with the translocation into the cell [34]. Further research needs to focus on the secondary structure of the CPPs in various conditions, and how they interact with cell membranes with the hope of revealing the connection between the structure and the peptide cell entry.


  1. Patel LN, ZaroJL, Shen WC. Cell Penetrating Peptides: Intracellular Pathways and Pharmaceutical Perspectives. Pharmaceutical Research. 2007; 24: 1977-1992.
  2. Brooks H, Lebleu B, Vivès E. Tat peptide-mediated cellular delivery: back to basics. Advanced Drug Delivery Reviews. 2005; 57: 559-577.
  3. Pujals S, Fernández-Carneado J, López-Iglesiasb C, Koganc MJ, Giralta E. Mechanistic aspects of CPP-mediated intracellular drug delivery: Relevance of CPP self-assembly. Biochimica Biophysica Acta (BBA) - Biomembranes. 2006; 1758: 264-279.
  4. Gerbal-chaloin S, Gondeau C, Aldrian-Herrada G, Heitz F, Gauthier-Rouvière C, Divita G. First step of the cell-penetrating peptide mechanism involves Rac1 GTPase-dependent actin-network remodelling. Biology of the Cell. 2007; 99: 223-238.
  5. Rothbard JB, Garlington S, Lin Q, Kirschberg T, Kreider E, McGrane PL, et al. Conjugation of arginine oligomers to cyclosporin A facilitates topical delivery and inhibition of inflammation. Nature Medicine. 2000; 6: 1253-1257.
  6. Fuchs SM, Raines RT. Pathway for Polyarginine Entry into Mammalian Cells. Biochemistry. 2004; 43: 2438-2444.
  7. Rothbard JB, Jessop TC, Lewis RS, Murray BA, Wender PA. Role of Membrane Potential and Hydrogen Bonding in the Mechanism of Translocation of Guanidinium-Rich Peptides into Cells. Journal of the American Chemical Society. 2004; 126: 9506-9507.
  8. Czajlik A, Meskó E, Penke B, Perczel A. Investigation of penetratin peptides Part 1. The environment dependent conformational properties of penetratin and two of its derivatives. Journal of Peptide Science. 2002; 8: 151-171.
  9. Liu XY, Timmons S, Lin YZ, Hawiger J. Identification of a functionally important sequence in the cytoplasmic tail of integrin beta 3 by using cell-permeable peptide analogs. Proceedings of the National Academy of Sciences of the United States of America. 1996; 93: 11819-11824.
  10. Zhang L, Torgerson TR, Liu XY, Timmons S, Colosia AD, Hawiger J, et al. Preparation of functionally active cell-permeable peptides by single-step ligation of two peptide modules. Proceedings of the National Academy of Sciences of the United States of America. 1998; 95: 9184-9189.
  11. Hawiger J. Noninvasive intracellular delivery of functional peptides and proteins. Current Opinion in Chemical Biology. 1999; 3: 89-94.
  12. Hallbrink M, Floren A, Elmquist A, Pooga M, Bartfai T, Langel U. Cargo delivery kinetics of cell-penetrating peptides. BBA - Biomembranes. 2001; 15: 101-109.
  13. Torchilin VP, Rammohan R, Weissig V, Levchenko TS. TAT peptide on the surface of liposomes affords their efficient intracellular delivery even at low temperature and in the presence of metabolic inhibitors. Proceedings of the National Academy of Sciences of the United States of America. 2001; 98: 8786-8791.
  14. Fittipaldi A, Ferrari A, Zoppé M, Arcangeli C, Pellegrini V, Beltram F, et al. Cell Membrane Lipid Rafts Mediate Caveolar Endocytosis of HIV-1 Tat Fusion Proteins. The Journal of Biological Chemistry. 2003; 278: 34141-34149.
  15. Ferrari A, Pellegrini1 V, Arcangeli C, Fittipaldi A, Giacca M, Beltram F. Caveolae-mediated internalization of extracellular HIV-1 tat fusion proteins visualized in real time. Molecular Therapy. 2003; 8: 284-294.
  16. Richard JP, Melikov K, Brooks H, Prevot P, Lebleu B, Chernomordik LV. Cellular Uptake of Unconjugated TAT Peptide Involves Clathrin-dependent Endocytosis and Heparan Sulfate Receptors. The Journal of Biological Chemistry. 2005; 280: 15300-15306.
  17. Wadia JS, Stan RV, Dowdy SF. Transducible TAT-HA fusogenic peptide enhances escape of TAT-fusion proteins after lipid raft macropinocytosis. Nature Medicine. 2004; 10: 310-315.
  18. Nakase I, Niwa M, Takeuchi T, Sonomura K, Kawabata N, Koike Y, et al. Cellular uptake of arginine-rich peptides: roles for macropinocytosis and actin rearrangement. Molecular Therapy. 2004; 10: 1011-22.
  19. Mano M, Henriques A, Paiva A, Prieto M, Gavilanes F, Simões S, et al. Cellular uptake of S413-PV peptide occurs upon conformational changes induced by peptide-membrane interactions. Biochimica Biophysica Acta (BBA) - Biomembranes. 2006; 1758: 336-346.
  20. Trabulo S, Cardoso AL, Mano M, Lima MC. Cell-Penetrating Peptides-Mechanisms of Cellular Uptake and Generation of Delivery Systems. Pharmaceuticals. 2010; 3: 961-993.
  21. Ter-Avetisyan G, Tünnemann G, Nowak D, Nitschke M, Herrmann A, Drab M, et al. Cell Entry of Arginine-rich Peptides Is Independent of Endocytosis. The Journal of Biological Chemistry. 2009; 284: 3370-3378.
  22. Ye J, Fox SA, Cudic M, Rezler EM, Fields GB, Terentis AC. Determination of Penetratin Secondary Structure in Live Cells with Raman Microscopy. Journal of the American Chemical Society. 2010; 132: 980-988.
  23. Duchardt F, Ruttekolk IR, Verdurmen WP, Lortat-Jacob H, Bürck J, Hufnagel H, et al. A cell-penetrating peptide derived from human lactoferrin with conformation-dependent uptake efficiency. The Journal of Biological Chemistry. 2009; 284: 36099-36108.
  24. Jiao CY, Delaroche D, Burlina F, Alves ID, Chassaing G, Sagan S. Translocation and Endocytosis for Cell-penetrating Peptide Internalization. The Journal of Biological Chemistry. 2009; 284: 33957-33965.
  25. Schmidt N, Mishra A, Lai GH, Wong GC. Arginine-rich cell-penetrating peptides. FEBS letters. 2010; 584: 1806-1813.
  26. Takechi Y, Tanaka H, Kitayama H, Yoshii H, Tanaka M, Saito H. Comparative study on the interaction of cell-penetrating polycationic polymers with lipid membranes. Chemistry and Physics of Lipids. 2012; 165: 51-58.
  27. Amand HL, Rydberg HA, Fornander LH, Lincoln P, Nordén B, Esbjörner EK. Cell surface binding and uptake of arginine- and lysine-rich penetratin peptides in absence and presence of proteoglycans. Biochim Biophys Acta. 2012; 1818: 2669-2678.
  28. Ryser HJ, Hancock R. Histones and basic polyamino acids stimulate the uptake of albumin by tumor cells in culture. Science. 1965; 150: 501-503.
  29. Mitchell DJ, Kim DT, Steinman L, Fathman CG, Rothbard JB. Polyarginine enters cells more efficiently than other polycationic homopolymers. The Journal of Peptide Researc. 2000; 56: 318-325.
  30. Wender PA, Mitchell DJ, Pattabiraman K, Pelkey ET, Steinman L, Rothbard JB. The design, synthesis, and evaluation of molecules that enable or enhance cellular uptake: Peptoid molecular transporters. Proceedings of the National Academy of Sciences of the United States of America. 2000; 97: 13003-13008.
  31. Saar K, Lindgren M, Hansen M, Eiríksdóttir E, Jiang Y, Rosenthal-Aizman K, et al. Cell-penetrating peptides: A comparative membrane toxicity study. Analytical Biochemistry. 2005; 345: 55-65.
  32. Lindberg M, Jarvet J, Langel U, Gröslund A. Secondary Structure and Position of the Cell-Penetrating Peptide Transportan in SDS Micelles As Determined by NMR. Biochemistry. 2001; 40(10): 3141-3149.
  33. Bechara C, Sagan S. Cell-penetrating peptides: 20 years later, where do we stand? FEBS letters. 2013; 587: 1693-1702.
  34. Eiriksdottir E, Konate K, Langel U, Divita G, Deshayes S. Secondary structure of cell-penetrating peptides controls membrane interaction and insertion. Biochim Biophys Acta. 2010; 1798: 1119-1128.
  35. Roccatano D, Colombo G, Fioroni M, Mark AE. Mechanism by which 2,2,2- trifluoroethanol/water mixtures stabilize secondary-structure formation in peptides: A molecular dynamics study. Proceedings of the National Academy of Sciences of the United States of America. 2002; 99: 12179-12184.

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Citation: Ye J. Cationic Cell Penetrating Peptides. Austin Biochem. 2016; 1(1): 1004.

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