General Conjugation Protocols of PEG linkers——PEG Maleimide
Polyethylene glycol (PEG) linker is a chemical sensing the carrier of polyethylene glycol (PEG), due to its solubility in water and non-immunogenicity. In the field of scientific research, it is widely used in chemical coupling, drug delivery, nanoparticles functionalized modifications and chemical biology. Its powerful function has attracted intense research interest. In the following, we will show the general conjugate reactions of nine common polyethylene glycol linkers one by one.
Condition: pH 5.5-7.5 PBS buffer (thiol free)
Introduction
2) Soluble in regular aqueous solution as well as most organic solvents.
3) Store at -20℃ and avoid frequent thaw and freeze.
4) Generally, a 10- to 20-fold molar excess of PEG-Maleimide over the amount of thiol-containing material results in sufficient conjugation.
Additional Materials Required
1) PEGylation buffer, PBS buffer, pH 7 or other thiol-free buffer at pH 7.
2) Maleimide stock solution: 100 mg in 1 mL conjugation buffer.
3) Washing solution: Distilled water or any aqueous buffer.
Procedure for thiol-bearing molecular modification with PEG Maleimide
1) Dissolve targeted materials in conjugation buffer and estimate the concentration thiol groups on the targeted materials.
2) Add PEG Maleimide stock solution to the targeted conjugation materials with the final concentration keep at least 10 mg/mL.
3) 10~20 molar excess of PEG maleimide needed for optimal conjugation.
4) The reaction mixture was stirred at room temperature for 2~4 hours or overnight at 4℃.
5) The final conjugate can be purified either by size exclusion chromatography, dialysis or other methods as needed.