4-Pentynoyl-Val-Ala-PAB-PNP

4-Pentynoyl-Val-Ala-PAB-PNP, a cleavable ADC linker used for synthesizing cryptophycin conjugates [1], is a click chemistry reagent that contains an alkyne group. It can undergo copper-catalyzed azide-alkyne cycloaddition (CuAAc) with molecules containing azide groups.