Boc-PEG4-Val-Cit-PAB-OH

Boc-PEG4-Val-Cit-PAB-OH is an enzyme-cleavable ADC linker featuring a Boc-protected amine, a hydrophilic PEG spacer, and a Val-Cit-PAB dipeptide. The benzylic alcohol on the PAB can be used to attach with reactive groups such as PNP for conjugation with drug payloads. The Boc protecting group may be removed with acid to reveal a primary amine which may be used in coupling reactions to form amides. The Val-Cit-PAB is cleaved by cellular proteases for efficient release of payloads to the cell.