Fc-binding Protein Amino Acid Substitutions Antibody Separation

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Solution Overview

Problem

Conventional Fc-binding proteins, such as FcyRIIIa, have limited antibody separation efficiency due to high affinity to antibodies, making it difficult to achieve accurate separation and analysis in industrial antibody drug production.

Innovation Solution

Amino acid substitutions in FcyRIIIa, specifically at position 192, reduce the protein's affinity to antibodies, allowing for improved separation efficiency when immobilized on an insoluble carrier, enabling high-accuracy antibody separation based on sugar chain structure and other properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional Fc-binding protein (FcyRIIIa) is used for antibody separation, then the separation process can be performed, but the separation accuracy and efficiency are insufficient due to high affinity to antibodies

Engineering Contradiction:
Improveantibody separation accuracyVSAvoidantibody separation efficiency
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent applies parameter changes by substituting specific amino acid residues (positions 43, 45, 51, 64, 91, 108, 133, 137, 187, and 192) in the FcyRIIIa protein sequence to modify its binding affinity characteristics. These amino acid substitutions change the physical-chemical parameters of the protein, resulting in decreased antibody binding affinity and improved separation accuracy while maintaining sufficient binding for separation purposes

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies local quality by making specific localized modifications at particular amino acid positions within the FcyRIIIa protein structure. Instead of changing the entire protein, targeted amino acid substitutions are introduced at specific sites (especially position 192) to locally alter the binding interface properties, achieving optimal balance between binding affinity and separation performance

Inventive Principle:
Principle #3Local quality

2Measurement precision

If amino acid substitutions are introduced to decrease antibody binding affinity, then separation accuracy improves, but protein structure and function may be affected

Engineering Contradiction:
Improveantibody separation accuracyVSAvoidprotein structure stability
Core Design Contradiction:
Measurement precisionVSStability of the object's composition

Solution Approach 1:

The patent carefully selects amino acid substitutions that change local binding properties without disrupting overall protein stability. The substitutions at positions 43, 45, 51, 64, 91, 108, 133, 137, 187, and 192 are chosen to modify binding affinity while preserving the structural integrity and functional capabilities of the FcyRIIIa protein

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies local quality by making specific localized modifications at particular amino acid positions within the FcyRIIIa protein structure. Instead of changing the entire protein, targeted amino acid substitutions are introduced at specific sites (especially position 192) to locally alter the binding interface properties, achieving optimal balance between binding affinity and separation performance

Inventive Principle:
Principle #3Local quality

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 modified Fc-binding protein with decreased antibody affinity enhances the accuracy and efficiency of antibody separation and analysis, facilitating process monitoring and quality control in antibody drug production.

Implementation Method 1

Fc-binding proteins, FcyRIIIa is known to recognize the sugar chain structure of an antibody (immunoglobulin). The antibody can be separated based on the sugar chain structure by using an adsorbent obtained by immobilizing FcyRIIIa on an insoluble carrier

Methodology Applied
Scientific EffectAffinity binding: Adsorption

Data Source

PatentEP3584257B1Fc-binding protein having improved antibody separation ability, and method for separating antibody using same
Publication Date: 2024.08.07 TOSOH CORP
  • EP3584257B1 patent drawingFigure 1~3
  • EP3584257B1 patent drawingFigure 4~6
  • EP3584257B1 patent drawingFigure 7~9

AI summary

The present invention addresses the problem of providing an Fc-binding protein having an improved antibody separation ability. The present invention also addresses the problem of providing a high-accuracy antibody separation method using an insoluble carrier having the protein immobilized thereon. The problems can be solved by: an Fc-binding protein in which at least an amino acid substitution at a specific position therein occurs and which has reduced affinity for an antibody; and an antibody separation method comprising a step of allowing an equilibration buffer solution to pass through a column in which an insoluble carrier having the protein immobilized thereon is filled to equilibrate the column, a step of adding a solution containing an antibody to cause the adsorption of the antibody onto the carrier, and a step of eluting the antibody adsorbed on the carrier using an elution solution.