Used in peptide synthesis as a building block for creating longer peptide chains. It helps in the stepwise assembly of peptides by providing a protective Fmoc group that can be easily removed during the process. Commonly employed in solid-phase peptide synthesis to produce custom peptides for research, drug development, and biochemical studies. Its sequence of glycine residues makes it useful for studying peptide structure and function, particularly in designing flexible peptide linkers or spacers in protein engineering.