Bromo-PEG4-t-butyl ester linker contains a bromide group and a t-butyl protected carboxyl group. The PEG spacer increases the aqueous solubility of the resulting compound. Bromo (Br) is a very good leaving group for nucleophilic substitution reactions. The t-butyl protected carboxyl group can be deprotected under acidic conditions to form a free acid for bioconjugation with amine-bearing biomolecules.
AxisPharm offers 5000+ PEG Linkers with high purity. Different kinds of PEG Reagents may be available by custom synthesis.