Maleimide-amido-PEG-propionic acid t-butyl ester

Maleimide-amido-PEG-propionic acid t-butyl ester is a heterotrifunctional reagent designed for multi-step bioconjugation, enabling sequential thiol-specific maleimide coupling, protected carboxyl group for acidic deprotection and subsequent functionalization, and amine-mediated modifications. Its key advantages include orthogonal reactivity for complex assemblies, tunable spacer length (n), and reduced steric hindrance due to the extended chain, though the t-Bu ester requires acidic deprotection and the maleimide group is sensitive to hydrolysis.