Efficient transfer of proteins or nucleic acids across cellular membranes is one of the technical challenges in cell biology. To deliver the functional domain of a selected protein from the outside to the inside of intact cells, a carrier is needed. Cell Penetrating Peptides, also known as Protein Transduction Domains (PTDs), are carriers with small peptide domains that can freely cross cell membranes. Several PTDs have been identified that allow a fused protein to efficiently cross cell membranes in a process known as protein transduction. Studies have demonstrated that a TAT peptide derived from the HIV TAT protein has the ability to transduce peptides or proteins into various cells.

AnaSpec’s GO™ Peptides include a vast offering of CPPs. We have CPPs such as (Arg)₉, Antennapedia, TAT and others. Offerings include green fluorescent labeled (e.g. FAM or FITC) CPP, red labeled (e.g. TAMRA), Cys conjugated CPPs or Cys(Npys) conjugated CPP. Npys stands for 3-nitro-2-pyridinesulfenyl. The S(Npys) group of a cysteine-containing peptide is capable of reacting selectively with the free thiol group of another cysteine-containing peptide to afford an unsymmetrical disulfide bond. This results in the conjugation of the CPP with the peptide cargo.

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Time-lapse video of FITC-LC-Antennapedia peptide (cat# 24175, 24176) entry into a neuronal cluster of cells. Video courtesy of Dr. E. Gruenstein, Univ. of Cincinnati Medical School, Cincinnati, OH.


Figure 1. Uptake of CPP by HeLa cells. HeLa cells were incubated with OptiMEM medium containing 10 uM FITC-LC-Antennapedia, cat# 24175, 24176 (panel A) and 10 uM of TAMRA-labelled TAT (47-57), cat# 61211(B) for 1 h, washed and analyzed by fluorescence microscopy.

Other CPP’s:

For a full listing of AnaSpec’s wide selection of CPPs, please click here.

Examples of peptides conjugated to (Arg)₉:

Bid BH3 - R9
Chimeric Rabies Virus Glycoprotein Fragment (RVG-9R)

References: Embury, J. et al. Diabetes 50, 1706 (2001), Wang, H. et al. J. Clin. Invest. 109, 1463 (2002); Lin, Y-Z. J. Biol. Chem. 270, 14255 (1995); Holzberg, D. et al. J. Biol. Chem. 278, 40213 (2003); Williams, E. et al. J. Biol. Chem. 272, 22349 (1997); Nakatani, KH. et al. Nat. Med. 10, 1128 (2004); Mortlock, A. et al. Nucleic Acids Res. 31, e152 (2003); Kaneto, H. et al. Nat. Med. 10, 1128 (2004); Wang, JL. et al. Cancer Res. 60, 1498 (2000); Oess S. and E. Hildt, Gene. Ther. 7, 750 (2000); Dunican, D. et al. Cell Growth Diff. 12, 255 (2001).