Multimeric IgG-Binding Ligand Structure for Oriented Immobilization
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Solution Overview
Problem
Existing methods for immobilizing immunoglobulin-binding proteins on supports do not optimize the number of linked domains to maximize IgG binding capacity, leading to potential steric hindrance and reduced binding efficiency.
Innovation Solution
Development of multimeric immunoglobulin-binding proteins with specific domain structures (R1)n-(R2)m or (R2)m-(R1)n, where only the (R2) domains are immobilized via reactive amino acids, allowing for oriented immobilization and maximizing IgG binding capacity without interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If multiple immunoglobulin-binding domains are linked to increase binding capacity, then the IgG binding amount increases, but steric hindrance occurs and binding efficiency decreases
Solution Approach 1:
The invention segments the immunoglobulin-binding protein into multiple independent binding domains (e.g., 5 domains per monomer) that are linked in a linear fashion. This segmentation allows each domain to function independently while maintaining optimal spacing, thereby increasing total binding capacity without significant steric hindrance between adjacent binding sites
Solution Approach 2:
The patent creates multimeric structures (dimers, trimers, tetramers, pentamers) by linking multiple monomers together, effectively transitioning from a single-domain structure to a multi-dimensional arrangement. This dimensional expansion increases the overall binding capacity distributed across multiple spatial locations, reducing local steric crowding while maximizing total IgG binding
2Quantity of substance
If the number of linked domains is increased to maximize binding capacity, then more IgG can be bound, but the complexity of determining the optimum structure increases
Solution Approach 1:
The invention systematically varies key parameters including the number of domains per monomer (standardized at 5), the number of monomers linked (2-5 monomers), and the type of linker peptides used. By establishing these standardized parameter ranges and evaluating their effects on binding capacity, the patent identifies optimal configurations without requiring exhaustive exploration of all possible structural variations
3Quantity of substance
If oriented immobilization is implemented to increase binding capacity, then IgG binding amount increases, but the immobilization process becomes more complex
Solution Approach 1:
The patent introduces cysteine residues at specific terminal positions (N-terminal or C-terminal) of the multimeric structure, creating localized reactive sites for immobilization. This local modification approach enables oriented single-point attachment to the support matrix while leaving the majority of binding domains untouched and available for IgG interaction, thereby simplifying the immobilization process compared to random multi-point attachment
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 optimized multimeric structure achieves higher IgG binding capacity with reduced immobilization amounts, enhancing antibody production efficiency and reducing costs.
Implementation Method 1
a protein having affinity to immunoglobulins... a multimeric immunoglobulin-binding protein having improved properties as an affinity ligand for affinity chromatography
Implementation Method 2
For immobilization of an immunoglobulin-binding protein on an insoluble support, reactivity of side chains of its amino acid residues are utilized
Data Source
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AI summary
Provided herein are a multimeric immunoglobulin-binding protein having improved properties as an affinity ligand for affinity chromatography, and an insoluble support immobilizing such a multimer. The immunoglobulin-binding protein is represented by the following general formula: (R1)n-(R2)m, or (R2)m-(R1)n, wherein R2 is an immunoglobulin-binding domain that includes an amino acid residue that covalently bonds to an insoluble support upon immobilization reaction with the insoluble support, and R1 is an immunoglobulin-binding domain that does not contain an amino acid residue the presence of which in the sequence compared to when it is absent in the sequence reduces the immunoglobulin-binding activity of the support yielded by the immobilization reaction. The immunoglobulin-binding protein satisfies the following conditions: (1) n is an integer of 5 to 9; (2) m is an integer of 1 or 2; (3) the n (R1) domains may or may not have the same sequence; and (4) the total number of domains (n + m) is 6 to 10.