Cation Exchange Chromatography Flow-Through Enrichment
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Solution Overview
Problem
There is a need for methods to enrich recombinant polypeptides with specific levels of post-translational modifications suitable for manufacturing, while maintaining acceptable product recovery and yield, as existing methods often fail to achieve the required levels of modifications such as sialylation or gamma-carboxyglutamate formation in recombinant polypeptides produced in cell lines.
Innovation Solution
The method involves using cation exchange chromatography (CEX) in a flow-through mode to separate recombinant polypeptides based on their binding affinity, where those that do not bind the CEX medium are enriched with higher levels of post-translational modifications compared to those that bind, thereby isolating the desired isoforms with enhanced sialylation or gamma-carboxyglutamate content.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional chromatography methods are used to enrich post-translational modifications, then the level of modification can be increased, but product recovery and yield are compromised
Solution Approach 1:
Instead of binding the desired highly modified polypeptides to the chromatography medium and eluting them, the patent inverts the approach by allowing highly modified polypeptides to flow through unbound while binding less modified forms to the medium. This inversion enables enrichment of the desired isoforms in the flow-through fraction, avoiding losses associated with binding and elution steps.
Solution Approach 2:
The patent extracts and removes the less modified polypeptide isoforms by binding them to the cation exchange chromatography medium, leaving the highly modified isoforms in the flow-through. This selective removal of unwanted forms achieves enrichment without subjecting the desired product to binding stress that would reduce recovery.
2Productivity
If cation exchange chromatography in flow-through mode is used, then product recovery is improved, but separation precision may be compromised
Solution Approach 1:
The patent utilizes changes in pH and ionic strength parameters to optimize the flow-through conditions. By carefully controlling these parameters, the method achieves both high recovery of highly modified polypeptides and effective separation from less modified forms, as the charge differences are maximized under specific conditions.
Solution Approach 2:
The patent replaces traditional mechanical separation methods with electrostatic interactions based on charge differences arising from post-translational modifications. This substitution enables highly selective separation based on molecular charge properties rather than size or other physical characteristics, achieving both high recovery and high precision.
3Manufacturing precision
If conventional binding-elution chromatography is used, then separation of isoforms is achieved, but process complexity and time are increased
Solution Approach 1:
The patent extracts the separation function into a single flow-through step where unwanted isoforms are removed by binding to the medium while desired isoforms pass through. This eliminates the need for subsequent elution and purification steps, simplifying the overall process while maintaining effective separation.
Solution Approach 2:
The flow-through mode enables continuous processing where the highly modified polypeptides are constantly enriched in the effluent stream. This continuous action eliminates the batch-wise binding-elution cycles, reducing process time and complexity while maintaining separation efficiency.
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 approach effectively enriches the recombinant polypeptides with increased sialic acid content or gamma-carboxyglutamate, improving their biological activity and therapeutic effectiveness by selectively removing impurities and maintaining high product yield, as demonstrated by the use of SE Hicap chromatography in enriching etanercept and other recombinant proteins.
Implementation Method 1
contacting a composition which comprises an initial population of recombinant polypeptides having different levels of post-translational modification with a cation exchange chromatography (CEX) medium operated in a flow-through mode; wherein recombinant polypeptides that do not bind the CEX medium are separated from recombinant polypeptides that bind the CEX medium
Data Source
AI summary
The present invention relates to improved methods in the separation recombinant polypeptides with post-translational modifications from complex mixtures through the use of a cation exchange medium.