PEG reagents are useful for coupling to functional groups of biologically active agents such as proteins, antibody fragments, aptamers, peptides, and small molecules. The chemical attachment of PEG to these biologically active agents is referred to as “PEGylation”. PEGylation reaction conditions vary depending on the biological active, 0the desired site and degree of PEGylation, and the PEG reagent. Factors to consider in the choice of a PEG reagent are:
- The desired functional point of attachment (amine, thiol, carboxyl, N-terminal, etc.);
- Activity of the conjugate and its pharmacokinetics;
- Multi-PEG species (PEGmers) and positional-PEG isomers;
- Immunogenicity of the conjugate.
Utopbio offers PEGylation services for our customers who wish for us to develop a PEGylation process, analytical methods, or PEG-conjugate purification.
PEGylation: Reagent selection, conjugate linkage, and conjugate stability (under physiological conditions)
Carboxyl PEGylation
mPEG-amine and a coupling agent Amide (stable)
Amine PEGylation
mPEG-NHS Esters (mPEG-SMB, -SPA or mPEG2-NHS) Amide
mPEG-Double Ester (mPEG-CM-HBA-NHS) Amide
N-terminal PEGylation
mPEG-ButyrALD and a reducing agent Secondary amine (stable)
mPEG-OPTE Secondary amine (stable)
Thiol PEGylation
mPEG-Maleimide Sulfide (stable)
mPEG-OPSS Disulfide (can be reduced)
mPEG-SH Disulfide (can be reduced)