This chemical is widely used in peptide synthesis, particularly in the development of peptide-based therapeutics and bioconjugates. Its Fmoc protecting group allows for selective deprotection during solid-phase peptide synthesis, enabling precise control over the assembly of peptide chains. The aminooxy functional group facilitates oxime ligation, a key reaction in bioconjugation, allowing for the attachment of peptides to other molecules, such as proteins, drugs, or fluorescent tags. The PEG4 spacer enhances solubility and flexibility, reducing steric hindrance and improving the efficiency of conjugation reactions. This makes it valuable in creating targeted drug delivery systems, diagnostic probes, and antibody-drug conjugates. Additionally, it is employed in the development of peptide-based vaccines and in the study of protein-protein interactions.