NHS ester-PEG4-Val-Cit-PAB-MMAE is a cleavable ADC linker used in the synthesis of antibody-drug conjugates (ADC). The Val-Cit is specifically cleaved by cathepsin B. As this enzyme is only present in the lysosome the ADC payload will be release only in the cell. The Boc group can be deprotected under acidic conditions to generate a free amine group.
AxisPharm offers 4000+ PEG Linkers with high purity. Different kinds of PEG Reagents may be available by custom synthesis.