Maleimide Linear PEGs from JenKem Technology (Methoxy PEG Maleimide) is is a thiol reactive PEG derivative selective for thiol groups on cystein side chains. Methoxy PEG Maleimide undergoes thiol PEGylation reactions with thiol-containing molecules at pH 5.0-6.5. Maleimide PEGylation products with molecular weights, branching, and functional groups not listed in our online catalog may be available by custom synthesis. Please inquire at firstname.lastname@example.org about pricing and availability of custom PEGylation products. Bulk PEGs and GMP PEGs are also available upon request. Please contact us for special bulk pricing.