Selenium-Containing PEG Reagents for Stable Protein Conjugation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current pegylation methods using PEG reagents with thiol and disulfide reactive groups face challenges such as formation of disulfide bonds that are easily cleaved in reducing environments, leading to unstable conjugates and site-specificity issues, particularly when modifying proteins like G-CSF, which requires a more stable and site-specific modification approach.
Innovation Solution
Development of modifying agents containing a reactive selenium group that forms a Se-S bond with thiol groups, allowing for site-specific pegylation of proteins like G-CSF, using water-soluble polymers like PEG, and enabling conjugate formation via a S-Se bond, which is more stable and can be performed in acidic conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If PEG reagents with thiol and disulfide reactive groups are used for pegylation, then site-specific modification is achieved, but the formed disulfide bonds are easily cleaved in reducing environments leading to instability
Solution Approach 1:
The invention changes the chemical parameter of the bonding mechanism by replacing disulfide bond formation with selenide bond formation. Selenium-containing PEG reagents react with thiol groups to form stable selenide bonds that are resistant to cleavage in reducing environments, while maintaining site-specific modification capability through selective reaction with cysteine residues.
2Quantity of substance
If PEGylation is performed on lysine amino groups, then the number of reaction sites is high, but complex mixtures with positional isomers and multipegylated forms are formed
Solution Approach 1:
The invention extracts the selenium-containing reactive group from conventional PEG reagents and introduces it to create a new class of PEG reagents that specifically target thiol groups. This selective targeting of cysteine residues (typically one or a few per protein) instead of lysine residues eliminates the formation of complex positional isomer mixtures while maintaining adequate reaction site availability.
3Ease of manufacture
If conventional PEG reagents are used for thiol modification, then disulfide bonds are formed, but these bonds require protecting groups and have limited stability
Solution Approach 1:
The invention creates a composite structure by incorporating selenium atoms into the PEG reagent molecule. This selenium-containing PEG composite reacts with thiol groups to form selenide bonds, combining the water solubility and shielding properties of PEG with the superior stability of selenide bonds, eliminating the need for protecting groups and enhancing overall conjugate stability.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The use of selenium-based modifying agents provides a stable and site-specific pegylation method for proteins like G-CSF, extending in-vivo half-life and reducing immunogenicity and proteolytic degradation, while allowing for efficient production and use in pharmaceutical compositions.
Implementation Method 1
the reactive selenium group being capable of reacting with a thiol group, preferably with a thiol group of a pharmaceutically active agent, thereby forming an -Se-S- bond
Data Source
Figure 1~5
Figure 6
Figure 7
AI summary
The invention relates to a modifying agent comprising a water soluble polymer, wherein the water soluble polymer comprises at least one reactive selenium group, said reactive selenium group being capable of reacting with a thiol group thereby forming an -Se-S- bond. Furthermore, the invention relates to a method for producing said modifying agents and their use in the modification of pharmaceutically active agents, e.g. G-CSF. Additionally, the invention concerns conjugates comprising a water-soluble polymer and a pharmaceutically active agent, wherein the water-soluble polymer is linked via a S-Se-bond to agent and a method for their production and their use as medicaments. Finally, the invention concerns a pharmaceutical composition comprising the inventive conjugates.