Bispecific Antibody Expression Tuning for Assembly Balance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Unbalanced expression of polypeptides in protein complexes, such as bispecific antibodies, leads to decreased yields and increased production of unwanted side-products, limiting the overall productivity in recombinant protein expression systems.
Innovation Solution
The method involves reducing the expression of the dominant chain by modifying transcription, translation, or mRNA stability and secondary structure to equilibrate the relative abundance of components, using codon deoptimization and optimization techniques in mammalian cells.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the expression level of one polypeptide is increased to maximize production yield, then the overall productivity increases, but the assembly of the desired protein complex is limited and unwanted side-products increase
Solution Approach 1:
The patent applies parameter changes by systematically varying the expression levels of individual polypeptides through different expression constructs, promoters, and codon optimization strategies. This allows tuning the relative abundance of each chain to achieve balanced stoichiometry in the final protein complex, resolving the contradiction between high productivity and proper assembly balance.
2Manufacturing precision
If the expression of the dominant chain is reduced to equilibrate relative abundance, then the assembly of the protein complex improves, but the overall expression level decreases
Solution Approach 1:
The patent applies local quality by differentially optimizing the expression of specific polypeptide chains within the complex. Rather than uniformly reducing all expression levels, the invention selectively modulates the expression of dominant chains while maintaining or enhancing the expression of limiting chains, thereby achieving local balance without sacrificing overall productivity.
3Manufacturing precision
If codon deoptimization is used to reduce expression of a specific polypeptide, then the relative abundance is equilibrated, but the total protein production decreases
Solution Approach 1:
The patent uses codon deoptimization as a controlled parameter change to specifically reduce the expression of dominant chains. By strategically selecting which codons to deoptimize in specific chains, the invention achieves the desired chain ratio while minimizing the impact on total protein production through compensatory optimization of other chains.
Data Source
Figure 1
Figure 2
Figure 3A~3B
AI summary
Methods are provided to improve the expression of protein complexes by tuning the expression levels of each component required for the assembly of the complex. These methods are effective in limiting the expression of the dominant chain and, thus, equilibrating their relative abundance. The methods provided herein lead to a significant increase in productivity and final bispecific yields both in transient expression systems as well as in stably transfected mammalian cells.