Fmoc-PEG4-Val-Ala-PAB-PNP is a cleavable PEG ADC linker with an Fmoc-protected amine. The Val-Ala peptide will specifically be cleaved by Cathepsin B. The Fmoc group can be deprotected under basic condition to obtain the free amine which can be used for further conjugations. PNP is a good leaving group. Reagent grade, for research purpose. Please contact us for GMP-grade inquiries.