FRET-Substrates

Overview of FRET-Substrates

FRET (Fluorescence Resonance Energy Transfer) is a distance-independent dipole-dipole interaction without photon emission, which causes energy to be transferred from the originally excited donor molecule to the acceptor molecule. It allows the detection of molecular interactions in the nanometer range. The FRET peptide is labeled with a donor molecule and a receptor (quencher) molecule. In most cases, the donor and acceptor pairs are two different dyes. If the acceptor is a non-fluorescent dye (quencher), the transfer energy from the fluorescent donor is converted to molecular vibration. When FRET is terminated (by separating the donor and acceptor), an increase in donor fluorescence can be detected. When both the donor and acceptor dyes are fluorescent, the transferred energy is emitted as longer wavelength light, so that the intensity ratio of the donor and acceptor fluorescence can be measured. For efficient FRET quenching, the fluorophore and quencher molecules must be close to each other (about 10-100) and the absorption spectrum of the quencher must overlap the emission spectrum of the fluorophore. When designing the donor-quencher FRET system, it is necessary to carefully compare the fluorescence spectrum of the donor with the absorption spectrum of the quencher.

Example of FRET-Substrates

1. Abz (F) substrates are generally used in combination with a number of quenchers (Q) such as Dnp (2, 4-dinitrophenyl), EDDnp (N-(2, 4-dinitrophenyl) ethylenediamine)
2. In a few substrates the fluorescent dansyl group (F) serves as donor with 4-nitro-phenylalanine as acceptor.
3. DMACA (F) can be detected fluorometrically at 465 nm using an excitation wavelength of 350 nm. It can be quenched by NBD (7-Nitro-benzo [2, 1, 3] oxadiazol-4-yl) (Q).

Our Advantages

Creative Peptides has extensive knowledge in the design and synthesis of peptide FRET substrates. We offer a variety of FRET substrates to meet your research needs, such as pre-fabricated FRET peptides or custom FRET sequences. As part of our service, we offer free consultation to help you design your FRET peptide and select the appropriate FRET pair.

References

1. Pires-Alves, M., Ho, M., Aberle, K. K., Janda, K. D., & Wilson, B. A. (2009). Tandem fluorescent proteins as enhanced FRET-based substrates for botulinum neurotoxin activity. Toxicon, 53(4), 392-399.
2. Yang, Y., Babiak, P., & Reymond, J. L. (2006). Low background FRET-substrates for lipases and esterases suitable for high-throughput screening under basic (pH 11) conditions. Organic & biomolecular chemistry, 4(9), 1746-1754.
3. Olga, A., Panagiota, S., Athanasios, A., & Emmanuel, M. (2017). Novel FRET-substrates of Rhizomucor pusillus Rennin: Activity and mechanistic studies. Food chemistry.