Single-Chain Antibody Separation Agent for Human Serum IgG Purification

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Solution Overview

Problem

Existing methods for obtaining antibodies using phage display technology often result in phages binding to antigens other than the target, due to protein denaturation and non-specific adsorption on tubes or plates, leading to reduced separation efficiency and antigen-binding capacity.

Innovation Solution

Using multilamellar liposomes coupled with antigens to facilitate specific binding of phages, allowing for high separation efficiency and antigen-binding capacity through lateral diffusion and easy antibody recovery.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If antigen is immobilized on tube or plate made of polystyrene, then phage binding can be performed, but non-specific adsorption occurs and protein denaturation leads to reduced separation efficiency

Engineering Contradiction:
Improveseparation efficiencyVSAvoidnon-specific adsorption
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces multilamellar liposomes as an intermediary carrier between the antigen and the phage library. The antigen is coupled to the liposome surface instead of directly to polystyrene tubes or plates. This intermediary liposome structure prevents non-specific adsorption and protein denaturation that occur with direct polystyrene immobilization, while still enabling specific phage-antigen binding. The liposome acts as a biocompatible mediator that maintains antigen integrity and reduces spurious binding events.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If blocking operation is performed to prevent non-specific binding, then some non-specific adsorption is reduced, but the process complexity increases and may still allow binding to denatured proteins

Engineering Contradiction:
Improvespecificity of phage bindingVSAvoidprocess complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent performs preliminary action by coupling the antigen to multilamellar liposomes before introducing the phage library. This pre-preparation of antigen-liposome conjugates ensures that the antigen is in an optimal state for specific binding from the outset, reducing the need for subsequent blocking operations. The liposome-antigen complex is pre-formed with proper orientation and conformation, preventing denaturation before the binding assay begins.

Inventive Principle:
Principle #10Preliminary action

3Ease of operation

If conventional immobilization methods are used, then simple operation is maintained, but protein denaturation occurs reducing antigen-binding capacity

Engineering Contradiction:
Improvesimplicity of immobilizationVSAvoidantigen-binding capacity
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent changes the physical and chemical parameters of the immobilization system by transitioning from direct polystyrene surface binding to liposome-mediated binding. The liposomes provide a different surface chemistry and physical environment that maintains antigen conformation and binding capacity. This parameter change in the carrier system allows for improved antigen-binding capacity while maintaining operational simplicity through standardized liposome coupling protocols.

Inventive Principle:
Principle #35Parameter changes

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 achieves high separation efficiency and antigen-binding capacity by reducing non-specific adsorption and enabling efficient recovery of target antibodies.

Implementation Method 1

a single-chain antibody which has a dissociation constant for a human serum-derived IgG polyclonal antibody of not more than 3.0 × 10^-8

Methodology Applied
Scientific EffectAntigen-antibody binding:

Data Source

PatentEP3375875B1Separating agent for human serum-derived igg polyclonal antibodies, and method for separating human serum-derived igg polyclonal antibodies using same
Publication Date: 2026.04.15 DAICEL CORP
  • EP3375875B1 patent drawingFigure 1
  • EP3375875B1 patent drawingFigure 2
  • EP3375875B1 patent drawingFigure 3

AI summary

An object of the present invention is to provide a separation agent for separating a human serum-derived IgG polyclonal antibody. This object is achieved by a separation agent for separating a human serum-derived IgG polyclonal antibody, the separation agent including: a carrier; and a single-chain antibody which has a dissociation constant for a human serum-derived lgG polyclonal antibody of not more than 3.0 × 10-8 M and which binds to the surface of the carrier via a chemical bond.