m-PEG-Mal, MW 40K is a thiol-reactive PEG derivative that is selective for thiol groups on cysteine side chains. m-PEG-Mal, MW 40K at pH 5.0-6.5 undergoes thiol PEGylation with thiol-containing molecules. PEG-MAL can be used for site-specific protein (cysteine) and peptide modifications.
AxisPharm offers 5000+ PEG Linkers with high purity. Different kinds of PEG Reagents may be available by custom synthesis.