Propargyl-PEG4-acid is a PEG linker with a propargyl and a terminal carboxylic acid group on the ends. While the terminal carboxylic acid can react with primary and secondary amine groups in the presence amide coupling reagents (e.g. EDC, or DCC) to form a stable amide bond, the propargyl group can be reacted with azide-bearing compounds or biomolecules via copper catalyzed azide-alkyne Click Chemistry to yield a stable triazole linkage. The increasing aqueous solubility derived from PEG spacer makes such linker an ideal conjugation linkers for biological applications.
AxisPharm offers 5000+ PEG Linkers with high purity. Different kinds of PEG Reagents may be available by custom synthesis.