Site-Specific Antibody Crosslinking via Enzymatic Handles
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Solution Overview
Problem
Current methods for creating bispecific antibodies lack site-specificity and directionality, leading to low yields and purification challenges due to random crosslinking and formation of undesirable multivalent species, which impairs antigen binding affinity.
Innovation Solution
The method involves site-specific crosslinking of antibodies, antibody fragments, or Fc-fusion proteins using glycosyl transferase-mediated attachment of chemical handles to terminal GlcNAc residues, followed by reaction with activating molecules containing crosslinking groups, ensuring directional and specific conjugation without genetic engineering.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If random crosslinking methods are used to create bispecific antibodies, then the process is simple, but the yield is low and purification is difficult due to formation of undesirable multivalent species
Solution Approach 1:
The patent applies local quality by introducing site-specific crosslinking at predetermined locations on the antibody molecules. Chemical handles are positioned at specific sites (e.g., Fc region) to enable controlled crosslinking only at these locations, preventing random crosslinking and formation of unwanted multivalent species, thereby improving yield and simplifying purification.
Solution Approach 2:
The patent employs preliminary action by pre-installing chemical handles at specific sites on the antibody molecules before crosslinking. This preparation step ensures that when crosslinking occurs, it happens only at the intended locations, controlling the reaction outcome and improving productivity without complicating the overall process.
2Device complexity
If random crosslinking is used, then the method is straightforward, but antigen binding affinity is impaired due to formation of multivalent species
Solution Approach 1:
The patent ensures reliable antigen binding affinity by restricting crosslinking to specific local sites on the antibody molecules. By positioning chemical handles at predetermined locations (such as the Fc region) and using site-specific crosslinking reagents, the method prevents formation of multivalent species that would impair antigen binding, while maintaining overall method simplicity.
3Manufacturing precision
If site-specific crosslinking is implemented, then antigen binding affinity is maintained and purification is simplified, but the method requires chemical handles and enzymatic modification
Solution Approach 1:
The patent uses an intermediary approach by introducing chemical handles as intermediaries between the antibody molecules and crosslinking reagents. These handles are installed at specific sites through enzymatic modification (e.g., glycosyl transferase) and serve as controlled interaction points, enabling site-specific crosslinking while managing the added complexity through a systematic two-step process.
Solution Approach 2:
The patent applies parameter changes by utilizing enzymatic modification to alter the chemical properties of specific sites on the antibody molecules. By changing the chemical structure at predetermined locations (e.g., adding chemical handles to Fc region residues), the method enables precise control over crosslinking specificity while managing process complexity through well-defined biochemical transformations.
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 maintains full antigen binding avidity, increases yields, and simplifies purification by limiting undesirable species, allowing for high-purity bispecific antibodies with preserved activity.
Implementation Method 1
contacting the first glycoprotein with the first modified sugar and a glycosyl transferase enzyme, wherein the glycosyl transferase enzyme catalyzes the attachment of the first modified sugar to the terminal GlcNAc residue of the first glycoprotein
Implementation Method 2
contacting the first modified glycoprotein with the first activating molecule, wherein the first activating molecule attaches to the first glycoprotein at the first chemical handle, thereby forming a first activated glycoprotein
Implementation Method 3
contacting the first activated glycoprotein with the second activated glycoprotein, wherein the first crosslinking group of the first activated glycoprotein reacts with the second crosslinking group of the second activated glycoprotein, thereby forming the crosslinked glycoprotein
Data Source
AI summary
Methods are provided for making bispecific antibodies and antibody conjugates comprising site-specifically cross-linking two or more antibodies, antibody fragments or Fc-fusion proteins. Also provided are compositions and uses for the bispecific antibodies and antibody conjugates. The bispecific antibodies may be used to treat a disease or condition. Also provided are methods for site-specifically conjugating a liposome, an mRNA or an siRNA to an antibody, and uses of the antibody-conjugated liposome, mRNA or siRNA.