Bispecific Antibody Assembly via Hinge Polypeptides and pH Control
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Solution Overview
Problem
Current methods for producing heteromultimeric proteins, such as bispecific antibodies, face challenges including low yields, aggregation, and reduced effector function due to issues like chemical cross-linking inefficiencies and limitations in recombinant DNA techniques, particularly in maintaining protein stability and achieving desired heterodimer formation.
Innovation Solution
The method involves optimizing conditions such as pH, using solubilizers like arginine and histidine, and reducing agents to stabilize and assemble hinge-containing polypeptides, allowing for efficient production of heteromultimeric proteins by forming assembly mixtures under controlled reducing conditions to enhance yield and prevent aggregation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If chemical cross-linking is used to produce bispecific antibodies, then heterodimer formation can be achieved, but the yield is low and aggregation occurs
Solution Approach 1:
The patent optimizes pH conditions during the assembly process, specifically maintaining pH 6.0-8.0 during the critical assembly phase to prevent aggregation while promoting heterodimer formation. This parameter control resolves the contradiction by creating conditions that favor productive assembly over aggregation.
Solution Approach 2:
The patent introduces a hinge-containing polypeptide as an intermediary component that facilitates controlled assembly. The hinge region acts as a mediator that brings the two half-antibodies into proper orientation and proximity, enabling efficient heterodimer formation without the aggregation problems associated with direct chemical cross-linking.
2Stability of the object's composition
If reducing conditions are applied to prevent aggregation, then protein stability improves, but assembly efficiency may be reduced
Solution Approach 1:
The patent applies reducing conditions in advance during the half-antibody preparation and storage phases to prevent aggregation, then removes or reduces these conditions during the assembly phase. This preliminary application of reducing agents protects the half-antibodies until they are ready for controlled assembly, resolving the contradiction between stability and assembly efficiency.
Solution Approach 2:
The patent employs periodic changes in redox conditions - maintaining reducing conditions during preparation and storage, then transitioning to oxidative conditions during assembly. This periodic switching allows the system to benefit from both reduced aggregation (during reduction) and efficient disulfide bond formation (during oxidation), resolving the apparent contradiction.
3Productivity
If pH is optimized for assembly, then heterodimer formation improves, but precipitation may occur
Solution Approach 1:
The patent carefully controls pH as a critical parameter, maintaining it within the narrow range of 6.0-8.0 during assembly. This parameter optimization ensures that the charge distribution on the proteins promotes heterodimer formation through electrostatic interactions while avoiding the pH extremes that would cause precipitation.
Solution Approach 2:
The patent creates a composite assembly environment by combining multiple components - half-antibodies with specific hinge regions, buffers at optimized pH, and controlled ionic strength. This composite system works synergistically to promote heterodimer formation while suppressing precipitation, as the multiple components collectively stabilize the desired assembly pathway.
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 significantly improves the yield and stability of heteromultimeric proteins by reducing aggregation and precipitation, leading to more efficient production of bispecific antibodies with maintained effector functions.
Implementation Method 1
using solubilizers like arginine and histidine, and reducing agents to stabilize and assemble hinge-containing polypeptides
Implementation Method 2
using solubilizers like arginine and histidine, and reducing agents to stabilize and assemble hinge-containing polypeptides, allowing for efficient production of heteromultimeric proteins by forming assembly mixtures under controlled reducing conditions
Data Source
AI summary
Described herein are methods for the efficient production of a heteromultimeric protein, such as a bispecific antibody. Heteromultimeric proteins may be capable of specifically binding to more than one target molecule or different epitopes on a single target molecule. The methods modulate parameters to improve assembly of the heteromultimeric proteins at higher yield and efficiency than otherwise possible. Also described are compositions comprising a hinge-containing polypeptide, such as a half-antibody.