PEG Conjugated Amino acid

BOC Sciences offers specialized PEGylation services for amino acids and other molecules such as antibodies, proteins and peptides. BOC Sciences has the comprehensive knowledge and capabilities to keep your project on track and drive success.

PEG Amino Acid

Since certain amino acids have low solubility in water, the introduction of PEG can greatly improve their water solubility, making them easier to dissolve and use in solution. Moreover, PEGylation can improve the stability of amino acids, preventing them from being degraded by light, heat, acid, alkali and other environmental factors. Aside from the purposes listed above, PEGylated amino acids may also have advantages in improving drug delivery properties, prolonging the circulation time of drugs in the body, reducing immunogenicity, regulating drug release rates, and controlling slow release properties.

Fig.1 One-Pot synthesis of PEG-Poly(amino acid) block copolymers. (Miyazaki et al., 2019)

How does PEG Couple Amino Acids?

PEG-NHS Coupling

PEG-NHS is a commonly used PEG activator that reacts with the amino groups in amino acids to form amide bonds. This method involves reacting PEG-NHS with the target amino acid under alkaline conditions to produce a PEG amino acid covalent linkage.

PEG-maleimide Coupling

PEG-maleimide is a PEG compound with a maleimide functional group that reacts with sulfhydryl residues in amino acids in a nucleophilic addition reaction.

PEG-isothiocyanate Coupling

This method is suitable for amino acids containing amino (NH₂) residues. PEG-isothiocyanate is a PEG compound with an isothiocyanate functional group that reacts with the amino group in amino acids to form a thiourea bond.

Amino Acid PEGylation Service

Synthesis of PEGylated amino acids

(1) Before synthesis, the design of the target structure is required. The type of amino acid, the length of the PEG chain, the selection and position of the functional group, etc. are designed according to the customer's requirements.

(2) Through the design of the molecule, different coupling methods can be selected and the corresponding PEG compounds can be chosen or customized. It is important to note that specific functional groups in the amino acids need to be protected if necessary, thus avoiding other reactions of the amino acids.

(3) Coupling reaction of the target PEG compound with the amino acid and post-processing steps, e.g., hydrolysis of the protecting groups, purification of the product, etc.

Optimization of Synthesis Process

For better scale-up and planning of PEGylated amino acids, the process for their preparation needs to be optimized.

• Optimization of PEG chain length
  The length of the PEG chain can affect the solubility and stability of PEGylated amino acids. Shorter PEG chains may provide better solubility but may have a greater impact on the stability of the amino acid. Longer PEG chains may provide better stability, but may reduce the solubility of the drug.
• Coupling position selection
  PEG can undergo coupling reactions with different functional groups of amino acids. Selection of the appropriate coupling position can affect the coupling efficiency of the PEG and the functionality of the amino acid. For example, coupling to the terminal end of an amino acid may affect the activity of its amine or carboxyl groups, while selecting a specific functional group on the side chain for coupling may be more appropriate.
• Modulation of coupling density
  Higher coupling densities may provide better stability, but may reduce drug solubility and biological activity. Lower coupling densities may provide better solubility and biological activity, but may affect stability.

Our Advantages

• Cutting-edge PEGylation technology
• Full range of assay equipment and platforms
• Multiple conjugation methods and choice of conjugation sites
• Characterization and analysis of PEG conjugated Amino acid
• Process optimization of PEG conjugated Amino acid

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