AAT Bioquest offers a comprehensive selection of FMOC-Glu(Dye) building blocks designed for in-sequence labeling of glutamic acid (Glu) residues during solid-phase peptide synthesis (SPPS). These pre-labeled amino acid derivatives enable researchers to incorporate fluorescent dyes, quenchers, and biotin tags directly into peptides at specific positions, making them essential tools for developing FRET-based protease substrates, fluorescent peptide probes, and biotinylated peptides for detection and purification applications.

FMOC-Glu derivatives labeled with fluorescent donor dyes are essential components for constructing FRET-based peptide substrates. These building blocks allow site-specific incorporation of fluorophores at glutamic acid positions during standard SPPS protocols. FAM and EDANS serve as classic green-emitting and blue-emitting donors, respectively, and commonly paired with DABCYL, while TAMRA and TF3 provide orange-emitting options for red-shifted FRET pairs.

Dark quencher-labeled FMOC-Glu derivatives serve as non-fluorescent FRET acceptors in peptide substrates. When incorporated into the same peptide as a fluorescent donor, these quenchers efficiently suppress donor fluorescence until the peptide is cleaved by a protease. DABCYL is the classic quencher paired with EDANS, while Tide Quencher™ (TQ) dyes offer superior quenching efficiency across broader wavelength ranges.

FMOC-Glu(biotinyl-PEG)-OH enables the incorporation of biotin tags at glutamic acid positions during peptide synthesis. The PEG spacer enhances water solubility and reduces steric hindrance, ensuring efficient streptavidin binding. This building block is particularly useful for creating biotinylated peptides for affinity purification, immobilization on streptavidin surfaces, or detection using streptavidin-conjugated reporters.