Polypeptide Interface Charge Tuning for Bispecific Antibody Assembly
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Solution Overview
Problem
Existing methods for producing bispecific antibodies are inefficient, leading to low production efficiency and nonuniformity, with only one out of ten antibodies being the desired bispecific type, and result in high production costs due to random covalent and non-covalent bonding of H and L chains.
Innovation Solution
Regulating the association between VH and VL peptides by substituting amino acids at the interface with charged amino acids, such as glutamic acid, aspartic acid, lysine, or arginine, to promote heterologous molecule formation, thereby enhancing production efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If random covalent bonding between H chains and non-covalent bonding between H and L chains is used, then antibody production is simple, but the proportion of desired bispecific antibody is very small (only 1 out of 10 types)
Solution Approach 1:
The patent applies local quality by introducing specific amino acid substitutions at the H chain interface regions (CH3 domain and VH domain) to create localized structural features that control association specificity. The substitutions are not random but targeted at specific positions to create complementary interfaces that promote heterologous H chain pairing while preventing homologous pairing.
Solution Approach 2:
The patent changes the chemical and physical parameters of the H chain interface by substituting amino acids with different properties (e.g., charge, hydrophobicity, size). These parameter changes create favorable conditions for heterologous association while disfavoring homologous association, thereby improving the proportion of desired bispecific antibody from 10% to significantly higher levels.
2Productivity
If amino acid substitutions are introduced into the IgG H chain CH3 region to promote heterologous H chain formation, then production efficiency improves, but the method is complex and requires multiple substitutions
Solution Approach 1:
The patent focuses modifications on specific local regions (CH3 domain and VH domain interfaces) rather than requiring multiple scattered substitutions throughout the antibody structure. This localized approach achieves effective control of H chain association with fewer, more targeted substitutions.
Solution Approach 2:
The patent introduces asymmetric amino acid substitutions that create complementary but non-identical interfaces between different H chains. This asymmetry ensures that heterologous chains (different types) associate preferentially over homologous chains (same type), as the asymmetric interfaces are designed to fit together like puzzle pieces rather than allowing identical chains to pair.
3Manufacturing precision
If multiple amino acid substitutions are made to promote heterologous molecule formation, then association control improves, but the number of substitutions increases complexity
Solution Approach 1:
The patent achieves precise association control by targeting substitutions to specific critical positions at the H chain interface (CH3 and VH domains) rather than distributing substitutions throughout the entire antibody structure. This localized precision allows effective control with fewer substitutions.
Solution Approach 2:
The patent designs substitutions in advance to create predetermined interface properties that naturally guide heterologous association. The amino acid substitutions are strategically placed to pre-establish favorable interaction patterns between different H chain types, eliminating the need for multiple trial substitutions or complex optimization steps.
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 method allows for the efficient production of heterologous molecules with fewer amino acid substitutions, maintaining functional integrity and reducing production costs by increasing the proportion of desired bispecific antibodies.
Implementation Method 1
substitution of two types of amino acids present at the VH-VL interface (four types for both chains) promotes the formation of the heterologous molecule
Data Source
AI summary
In the course of the present invention, it was discovered that one could regulate association between polypeptides by modifying amino acid residues that form the interface during the association to amino acids carrying the same type of charge. In this context, the present invention enables efficient formation of heterologous molecules. For example, the present invention can be suitably applied to the preparation of bispecific antibodies.