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 (CPPs), 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 Poly-Arg, Antennapedia, TAT, Transportan
and others. These peptides are available as green fluorescent labeled (e.g. FAM or FITC),
red labeled (e.g. TAMRA), Cys conjugated or Cys(Npys) conjugated. Npys
stands for 3-nitro-2-pyridinesulfenyl. The 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 (Table 1).
Recent releases of CPPs include two Beclin-1, TAT conjugated peptides for use in autophagy research (Table 2). Newly released CPP's also include KALA and others (Table 3).
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.
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