Custom Protein-PEGylation Conjugation Service

Introduction of Polyethylene Glycol

Polyethylene Glycol (PEG) is a generic term for glycol polymers with a relative molecular mass of 200-8000 and above, with the chemical structure of HO-(CH₂CH₂)_n-OH. PEG is FDA-approved for in vivo use due to its non-toxicity, non-immunogenicity, precise molecular weight, high purity, and low polydispersity.

PEG Derivatives

In order to maintain the specificity of the PEGylation, a methyl group is usually added to protect the alcohol hydroxyl group at one of its termini, turning it into methoxy PEG (mPEG). This modification allows for better control and precision in the PEGylation process. Moreover, the low bioactivity of the hydroxyl group at the raw end of polyethylene glycol makes it challenging to achieve stable binding with substrates. Consequently, the scope of modification for proteins, peptides, and other drugs becomes relatively narrow. Functionalized groups, such as N-hydroxysuccinimide (NHS), amino, carboxyl, aldehyde, and p-toluenesulfonic acid salts, have been widely used for the modification of mPEG. These functionalized mPEG derivatives provide a broader range of possibilities for the modification and enhancement of various biomolecules and drugs.

Our PEGylated Conjugation Services

PEGylated technology couples PEG with the modified drugs through covalent bonding. This innovative approach aims to enhance the physicochemical properties and biological activity of the compounds. PEGylation has found extensive applications in various areas including proteins (peptides), enzymes, antibodies, and small molecules. Creative Biolabs offers different methods of PEGylation depending on the molecular structure, weight, and physicochemical properties of the modified compounds.

Lysine-Based Random Conjugation Services

Lysine is usually present in high quantities on the surface of proteins. When protein modification is carried out using ε-NH2 of lysine as the target, a series of PEG chains with different lengths can be formed, resulting in a product that is a mixture of PEGylated isomers.

Site-Specific Conjugation Services

Site-specific PEGylation is achieved through the optimized selection of coupling modes, PEG crosslinkers, reacting conditions (like pH), etc. The products obtained from this conjugation are homogeneous, with fewer isomers, better retention of activity, and greatly reduced immunogenicity. we offer the following site-specific PEGylation methods.

A. PEG-aldehyde and pH adjustment selectively modify N-terminal α-amin

B. PEG-maleimide, PEG-vinylsulfone, PEG-iodoacetamide, and PEG-n-pyridyl disulfide react with sulfhydryl to form stable disulfide bonds

C. PEGylated derivatives with hydrazides are coupled to carboxyl groups of proteins and peptides

D. Enzyme catalysis leads to selective PEGylation of proteins with complex structures

Fig.2 PEGylation methods for proteins. (Creative Biolabs Original) Fig. 2 Strategies for site-specific PEGylation.

At Creative Biolabs, quality is our top priority. We adhere to strict quality control measures to ensure that your PEGylated compounds meet the highest standards of excellence. More importantly, our professional team can provide custom conjugation services according to your specific objectives. We look forward to providing you with an exceptional experience. If you are interested in our services, please contact us for more information.