peptides, peptides with a reporter fluorescent dye, are valuable probes used
in visualizing intracellular processes and
molecular interactions at the level of single cells.1 The fluorescent dye can
be attached to the amino (N) or carboxy (C)-terminus, or in the case of FRET
or Förster resonance energy transfer) peptides, the two dyes (donor and acceptor)
can be at the amino and carboxy termini or in the internal peptide sequence.
our dual expertise in peptides and fluorescent dyes, AnaSpec is pleased to offer
a broad selection of fluorescently labeled peptides labeled with our proprietary
HiLyte™ Fluor dyes, as well as classic dyes (FAM, FITC, TAMRA).
For use as enzyme activity detection probes
Peptide substrates used in detection of enzyme activity
can contain either a single dye or in the case of FRET, two dyes. In the intact
fluorescent substrates, there is low fluorescence prior to enzyme hydrolysis.
Upon recognition of the substrate by a specific enzyme and subsequent cleavage,
the quenched fluorescence is recovered. Increase in fluorescence is correlated
to enzyme activity.2-3 AnaSpec's
single dye-labeled fluorescent peptide selection include substrates for kinases,
and others. Our FRET peptides, generally consisting of a dye (donor) and a non-fluorescent
quencher (acceptor), include substrates for MMPs, Aggrecanase-1,
HCV, HIV, cathepsins, renin, ACE2,
For use as targeting probes
Fluorescent peptides have been used in in vivo or in vitro
studies for visualizing cellular processes and molecular interactions.1
In in vivo imaging, three-dimensional fluorescence images of the internal
structures, especially of small animals, are produced. This technique requires
the use of near infrared red (NIR) dyes since at higher wavelength, tissues
do not absorb or scatter photons as strongly as when lower wavelength dyes are
used.2-3 An example is an RGD peptide, c[RGDyK(HiLyte™ Fluor
750)], that AnaSpec synthesized for J. Rey of the Univ. of South Florida. This
peptide was shown to bind preferentially to organs that are known to be rich
in integrin αvβ3 (see poster for
details). Another examples are the fluorescent cell penetrating peptides,
TAT (47-57), cat# 61211 (Fig. 1).
|Figure 1. HeLa cells were incubated
with OptiMEM medium containing 10 uM FITC-LC-Antennapedia, cat# 24175, 24176
(panel A) and 10 uM of TAMRA-labeled TAT (47-57), cat# 61211(B) for 1 h,
washed and analyzed by fluorescence microscopy.
Related Products and Services
of SensoLyte® assay kits (majority FRET-based)
1. Pap, EHW. et al. Exp. Cell Res. 265, 288 (2001).
2. Lakowicz, Joseph. Principles of Fluorescence Spectroscopy. New
York: Springer, 2006.
3. Tung, C-H. Peptide Sci. 76, 391 (2004).