Internally Quenched Peptides / FRET Peptides

JPT’s internally quenched peptides or FRET peptides are guaranteed to be free of fluorescent impurities. Fluorescence Resonance Energy Transfer (FRET) peptides are widely used in various fields such as biochemistry, molecular biology, and drug discovery. These specialized peptides allow researchers to study biological interactions, enzymatic activities, and protein-protein interactions in real-time through energy transfer between a donor fluorophore and an acceptor quencher.

Key Benefits of FRET Peptides:

Real-time monitoring of enzymatic reactions and protein activity.
Highly sensitive detection due to the unique proximity-based energy transfer.
Versatility in both in vitro and in vivo applications, providing insight into complex biological processes.

The most frequently used dye/quencher combinations and common attachment options are shown below.

Fluorophore	Quencher	Excitation / Emission Wavelength
Abz 2-Aminobenzoyl	Dnp 2,4-dinitrophenyl	320 nm 420 nm
Abz 2-Aminobenzoyl	NitroTyr 3-nitro-tyrosine	320 nm 420 nm
Mca 7-Methoxycoumarin-4-yl)acetyl	Dnp 2,4-dinitrophenyl	325 nm 392 nm
Trp Tryptophan	Dnp 2,4-dinitrophenyl	280 nm 360 nm
EDANS 5-[(2-Aminoethyl) amino] naphthalene-1-sulfonic acid	Dabcyl 4-([4'-dimethylamino)phenyl]azo)benzoyl	340 nm 490 nm
FAM Carboxyfluorescein	Dabcyl 4-([4'-dimethylamino)phenyl]azo)benzoyl	492 nm 517 nm
Lucifer Yellow	Dabsyl 4-(Dimethylamino)azobenzene-4'-sulfonyl	430 nm 520 nm

Attaching Fluorophores and Quenchers: Options and Techniques

JPT's FRET peptides are engineered with precision to ensure accurate attachment of the fluorophore and quencher. The most common attachment options include N-terminal and C-terminal conjugation, ensuring flexibility in peptide design. These approaches allow for custom FRET probes tailored to the specific needs of a given experiment.

Considerations for Choosing FRET Pairs:

Spectral Compatibility: It's essential to choose a FRET pair with minimal overlap between the excitation and emission spectra to maximize detection accuracy.
Peptide Sequence: The efficiency of energy transfer is distance-dependent, making the length of the peptide crucial for proper FRET signal generation.
Quenching Efficiency: Some quenchers, like Dabcyl and Dnp, are highly effective in suppressing background fluorescence, making them suitable for sensitive assays.

Applications of Internally Quenched Peptides in Research

Internally quenched FRET peptides have transformed how researchers study dynamic biological processes. Their use is widespread in several key areas, including:

Protease activity assays: By incorporating a cleavage site between the fluorophore and quencher, enzymatic cleavage can be directly monitored.
Drug discovery: High-throughput screening of potential drug candidates relies on FRET peptides to track biological interactions.
Molecular diagnostics: Internally quenched peptides are increasingly used in detecting disease biomarkers in clinical samples.

Custom FRET Probes and Peptides from JPT

JPT offers a range of pre-designed and custom FRET probes, ensuring they meet the specific requirements of your research. Our peptides are guaranteed to be free of fluorescent impurities, providing accurate, reproducible results.

Our custom FRET peptides are developed to the highest quality standards, allowing for flexibility in fluorophore-quencher pair selection. Whether for enzymatic studies, drug screening, or molecular diagnostics, our FRET probes provide reliable and sensitive results.