NH2-PEG3-Val-Cit-PAB-OH

NH2-PEG3-Val-Cit-PAB-OH is a cleavable ADC (antibody-drug conjugate) linker characterized by a primary amine, a hydrophilic PEG spacer, a Val-Cit dipeptide, and a PAB group. The benzyl alcohol on PAB facilitates conjugation with reactive groups like PNP, enabling attachment to drug payloads. The primary amine readily participates in various reactions such as coupling with carboxylic acids, reductive amination with ketones or aldehydes, and other specialized applications like SNAr reactions or heterocyclic chemistry. The Val-Cit dipeptide is cleaved by intracellular proteases, allowing efficient payload delivery through an elimination mechanism within the PAB structure.