endo-BCN-PEG4-t-butyl ester contains a BCN group and a t-butyl protected carboxyl group.The BCN group readily reacts with azide-bearing molecules to form bicyclic triazole linkage. The t-butyl ester can be easily de-protected to form carboxyl acid that can undergo further amide coupling and conjugate onto another biomolecule through standard acid/amine or acid/hydroxyl coupling conditions. The hydrophilic PEG spacer can drastically increase solubility in aqueous media.
Axispharm offers 3000+ PEG Linkers with high purity. Different kinds of PEG Reagents may be available by custom synthesis.