Recombinant GCSF Refolding via High pH Solubilization
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Solution Overview
Problem
Current methods for refolding Granulocyte Colony Stimulating Factor (GCSF) from inclusion bodies result in high levels of oxidized impurities, leading to sub-optimal yields of biologically active protein, as they generate significant amounts of oxidized forms during solubilization and refolding, necessitating additional purification steps.
Innovation Solution
An optimized solubilization process is employed by solubilizing inclusion bodies at pH 11 to 12 without incubation, followed by the addition of a refolding buffer containing a basic amino acid and a polyalcohol, and then a redox shuffling mixture with cysteine and cystine, to reduce oxidized forms of GCSF to less than 1.5%, thereby improving the yield of correctly folded protein.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional solubilization and refolding methods are used, then GCSF can be obtained from inclusion bodies, but high levels of oxidized impurities are generated resulting in sub-optimal yields
Solution Approach 1:
The patent changes the pH parameter during solubilization from conventional lower pH values to pH 11-12, which prevents oxidation of methionine residues. This parameter change directly addresses the contradiction by modifying the chemical environment to reduce harmful oxidation while maintaining protein solubility and eventual refolding capability
Solution Approach 2:
The patent applies preliminary protection against oxidation during the solubilization step by maintaining high pH conditions before refolding occurs. This preliminary action prevents the formation of oxidized impurities that would otherwise require subsequent removal steps, thereby improving overall yield of active protein
2Productivity
If conventional refolding methods are used, then GCSF is produced, but additional purification steps are required to remove oxidized impurities
Solution Approach 1:
By changing the pH parameter to 11-12 during solubilization, the patent eliminates the need for additional purification steps to remove oxidized impurities. This single parameter change simplifies the overall process while maintaining high productivity, as the high pH condition prevents oxidation at its source rather than requiring downstream removal
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
This method significantly reduces the generation of oxidized forms of GCSF, enhancing the yield of correctly folded biologically active protein and minimizing the need for downstream purification steps to remove oxidized impurities.
Implementation Method 1
solubilizing inclusion bodies at pH 11 to 12 without incubation
Implementation Method 2
addition of a redox shuffling mixture with cysteine and cystine, to reduce oxidized forms of GCSF to less than 1.5%
Data Source
Figure 1
AI summary
The present invention is related to a method for refolding of recombinant GCSF that minimizes the generation of oxidized forms of GCSF by optimizing the refolding of inclusion bodies containing recombinant GCSF.