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Custom Peptides
FRET Peptides
As a world leader in FRET (fluorescence resonance energy transfer) peptide technologies, we propose a full range of dye-quencher pairs for customized assay developments.
Our dye/quencher labeling offer
We offer a full-range of dye-quencher FRET pairs and fluorogenic substrates.
The tables below list the dyes and quenchers available to label your custom peptides
| FRET Pairs | ||
|---|---|---|
| Dye (donor) | Quencher (acceptor) | Donor Ex/Em |
| Mca | Dnp |
•
325/393 nm |
| EDANS | DABCYL, DABCYL Plus, QXL®490 |
•
335/493 nm |
| FAM | QXL®520 |
•
492/518 nm |
| FITC | QXL®520 |
•
494/519 nm |
| HiLyte™ Fluor 488 | QXL®520 |
•
502/527 nm |
| CyLyte Fluor 3 | QXL®570 |
•
550/564 nm |
| HiLyte™ Fluor 532 | QXL®570 |
•
545/565 nm |
| HiLyte™ Fluor 555 | QXL®570 |
•
550/566 nm |
| TAMRA | QXL®570 |
•
541/568 nm |
| Rox | QXL®610 |
•
568/591 nm |
| CyLyte Fluor 5 | QXL®670 |
•
648/663 nm |
| HiLyte™ Fluor 647 | QXL®670 |
•
650/675 nm |
| CyLyte Fluor 7 | IR-QXL® |
•
750/773 nm |
QXL® and Dye pairings are available from our custom labeling services & from our catalog SensoLyte® protease activity assay kits
(ie., QXL® 520 - HiLyte™ Fluor 488, QXL® 520 - FAM)
Fluorogenic Substrates
Fluorogenic substrates do not require a quencher and contain a C-terminal dye that does not fluoresce until it is cleaved from the peptide (fluorescent form of dye is released).
| Fluorogenic substrate dyes | |
|---|---|
| Dye | Ex/Em |
| AMC |
•
351/430 nm |
| AFC |
•
382/480 nm |
| Rh110 |
•
501/527 nm |
Why use FRET?
FRETand fluorogenic substrates are more sensitive than chromogenic substrates with linear dynamic range and great reproducibility.
FRET-based peptides are used in a variety of applications, with high benefit when used as protease substrates in high-throughput inhibitor screening & drug discovery.
Benefits
Using Dyes and Quenchers from AnaSpec (Eurogentec's US subsidiary) offers many advantages:
- Unique collection of proprietary quenchers (QXL®) which tandem with the most popular dyes
- Top quality HiLyte™ Fluor dyes
- Access to the Cy dyes at an affordable price (CyLyte dyes which have identical structures to the trademarked Cy®)
- Longer wavelengths for improved sensitivities
- Easy adaptation to high throughput screening assays
Applications
- Protease activity detection & measurement
- Protease-based drug target screening and discovery
- High throughput screening of protease inhibitors
FRET principle
FRET occurs when a donor (fluorophore) and an acceptor (quencher) are in close proximity (within 10-100Å from each other). The energy from the excited fluorophore is transfered to the quencher resulting in no fluorescence emission.
If the donor and acceptor are on a same peptide which is a protease substrate, enzymatic hydrolysis will result in spatial separation of the donor from the acceptor, and fluorescence emission.
Featured Citations
FRET-based trilateration of probes bound within functional ryanodine receptors.
Bengt Svensson,Tetsuro Oda, Florentin R.Nitu, Yi Yang, Iustin Cornea, Ye Chen-Izu, James D.Fessenden, Donald M.Bers, David D.Thomas, Razvan L.Cornea1
Biophysical journal. 2014 Nov 4;107(9):2037-48. https://doi.org/10.1016/j.bpj.2014.09.029From AnaSpec (Eurogentec's US subsidiary) : DPc10 peptides either unlabeled, or labeled with HiLyte Fluor 647 (HF647)
AMCA to TAMRA long range resonance energy transfer on a flexible peptide.
A. Synak, R.Fudala, I.Gryczynski, L.Kułak, S.Shah, I. E. Serdiuk, B. Grobelna, P.Arłukowicz, A.Kubicki, P.Bojarski
Dyes and Pigments. 2018 Nov;158:60-64From AnaSpec (Eurogentec's US subsidiary) : Lys(AMCA)-Gly-Pro-Arg-Ser-Leu-Ser-Gly-Lys(TAMRA)-NH2 peptide