Anaspec is offering a broad selection of fluorescent peptides labelled with its Hilyte Fluoro dyes, as well as classic dyes (FAM, FITC, Tamra).
Peptide substrates used in the 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.
Anaspec's single dye-labelled fluorescent peptide selection include substrates for kinases, caspases, cathepsins, HDAC (histone deacetylase), calpain, kallikrein, and others.
Its 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, A and B-secretases and others.
Fluorescent peptides have been used for in vivo or in vitro studies for visualising cellular processes and molecular interactions.
For in vivo imaging, 3D fluorescence images of the internal structures, especially of small animals, are produced.
This technique requires the use of near infrared (NIR) red dyes, since at higher wavelength, tissues do not absorb or scatter photons as strongly as when lower wavelength dyes are used.
An example is an RGD peptide, c[RGDyK(Hilyte Fluoro 750)], which Anaspec synthesised for J Rey of the University of South Florida.
This peptide was shown to bind preferentially to organs that are known to be rich in integrin avb3.
Other examples are the fluorescent cell penetrating peptides, FITC-LC-Antennapedia and Tamra-labelled TAT (47-57).
