Peptide linkers belong to protease-sensitivity linkers (also called enzymatically cleavable linkers) that have gained significant attention in ADC development due to their superior plasma stability and controlled payload release mechanism. The core structure of a peptide linker comprises of either a di-peptide or a tetra-peptide that is recognized and cleaved by lysosomal enzymes to ensure the intracellular drug release once the ADC is internalized and trafficked to the lysosome. Based on the core, additional components are added to the short peptide to facilitate antibody conjugation (e.g. Maleimide or PEG-Maleimide) or drug release (self-immolated moieties such as para-amino benzyl alcohol) in its most “native” form, another feature that makes peptide linkers appealing choices for ADC applications.

With years of experience in the design and synthesis of protected amino acids and peptides,   APINNOTECH Co., Ltd has successfully produced a series of peptide linkers with a total capacity to 200 kgs per year.