17-(Bromoacetamido-PEG9-ethylcarbamoyl)nonanoic 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. The bromoacetamide is a very good leaving group for nucleophilic substitution reactions and is widely used for cysteine thiol labeling and capping. The t-butyl protected carboxyl group can be deprotected under acidic conditions to from a free carboxylic acid that can undergo bioconjugation with amine-containing biomolecules.
Axispharm offers 3000+ PEG Linkers with high purity. Different kinds of PEG Reagents may be available by custom synthesis.