Used in solid-phase peptide synthesis as a protected amino acid derivative, enabling selective side-chain protection for aspartic acid or glutamic acid residues. Its Fmoc group allows for mild base deprotection, compatible with standard peptide assembly protocols. The 4-Amb (4-aminomethylbenzoic acid) moiety acts as a linker in the synthesis of peptide libraries or conjugates, particularly useful in the development of peptide-based drugs, probes, and bioconjugates. Commonly employed in research settings for creating C-terminal modified peptides and in the preparation of peptide amides.