Fmoc-PEG4-Val-Ala-PAB from AXISPHARM is a cleavable antibody-drug conjugate (ADC) linker with an Fmoc-protected amine. The Fmoc group can be deprotected under basic conditions to give the free amine. The Val-Ala peptide is specifically cleaved by Cathepsin B.
AxisPharm offers 5000+ PEG Linkers with high purity. Different kinds of PEG Reagents may be available by custom synthesis.