m-PEG4-NH-Mal linker contains a maleimide group. The maleimide group react specifically with a thiol group to form a covalent S-C bond. The mPEG modification increases the aqueous solubility of the resulting compound.
AxisPharm offers 4000+ PEG Linkers with high purity. Different kinds of PEG Reagents may be available by custom synthesis.