Does Bio-Synthesis offer custom FRET peptide synthesis?
Yes, Bio-Synthesis offers custom FRET peptide synthesis and also has a large selection of stock FRET peptides ready to use. The synthesis of peptides conjugated to fluorochromes and quencher molecules for Förster resonance energy transfer or fluorescence resonance energy transfer (FRET) analysis is also possible.
Fluorescence-quencher pairs must have a perfect spectral overlap between the fluorochrome's emission spectrum and the absorbance spectrum of the quencher. The quencher placed within a limited distance from the fluorochrome blocks the fluorochrome's emission. The FRET peptide can be split into two pieces, for example, via enzymatic degradation. This event increases the distance between the quencher and the fluorophore, which now activates the fluorochrome. The intensity of the fluorescence is proportional to the degradation of the peptide.
Bio-Synthesis offer several FRET Peptide modifications:
- Abz/DNP - Can be used as Internally Quenched Fluorescent Peptide Substrates
- EDANS/FAM or Tyr (NO2)3
- EDANS/DABCYL or DABSYL
- TAMRA/TQ3 or QSY-7
- Eu(III) Chelate/TQ3 or QSY-7
- 5-FAM/TQ2, TMR or other quencher
- MCA (Methoxy-coumarin-acetic-acid) / DNP (2,4-Dinitrophenyl
- DY630/DQ660
The Fluorescence/quencher pair most often used is the Abz/Dnp pair. However, the Abz/Dnp pair has the highest success rate in peptide synthesis. The fluorochrome Abz, conjugated to the N-terminus, has an Excitation spectrum of 320 nm and an Emission spectrum of 420 nm, respectively. In general, the Dnp quencher is conjugated either internally or to the C-terminus to the primary amino group on a lysine residue.
The EDANS/Dabcyl pair is an alternative to the Abz/Dnp pair. However, this pair is significantly more expensive to synthesize and more complicated to conjugate during peptide synthesis than the Abz/Dnp pair. Excitation and emission spectrum peak wavelengths of the EDANS fluorochrome are 336 and 490 nm, respectively. The emission maximum for Dabcyl is 472 nm.
Fluorogenic peptide substrates are used in peptide assays such as assays for matrix metalloproteinases as well as other proteolytic enzymes.
Contact Bio-Synthesis for FRET Peptide Synthesis Services.