Site-Specific Antibody Conjugation via Enzymatic Labeling

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Solution Overview

Problem

Existing antibody labeling methods result in poor homogeneity and degradation of antibody function due to random attachment of foreign substances, which is a barrier to the development of antibody-drug conjugate technology requiring high safety and reproducibility.

Innovation Solution

A method for specifically transferring chemical functional groups to certain sites of an antibody, such as lysine 246 or 248, allowing for site-specific linkage of desired numbers of cargo moieties without additional antibody modification, using click chemistry functional groups and peptide conjugates to enhance antibody-drug conjugate efficacy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If random labeling method is used to attach foreign substances to antibody, then the labeling process is simple, but the homogeneity of antibody preparation deteriorates and antibody recognition ability is degraded

Engineering Contradiction:
Improvelabeling process simplicityVSAvoidantibody labeling homogeneity
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent introduces a site-specific labeling method that targets particular amino acid residues (such as lysine at position 246 or 248 in the Fc region) of the antibody. This approach ensures that foreign substances are attached only at predetermined locations, achieving high homogeneity in the number and position of attached moieties while maintaining antibody recognition ability. The method uses enzymes like transglutaminase or sortase to catalyze specific reactions at targeted sites, resolving the contradiction between simple manufacturing and high precision labeling.

Inventive Principle:
Principle #3Local quality

2Ease of manufacture

If random labeling method is used to attach foreign substances to antibody, then the labeling process is simple, but the antibody recognition ability is significantly degraded

Engineering Contradiction:
Improvelabeling process simplicityVSAvoidantibody recognition ability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent employs site-specific labeling at predetermined amino acid residues in the Fc region, away from the antigen-binding Fab regions. This localized approach prevents interference with antibody recognition ability while achieving effective labeling. The use of specific enzymes ensures that modifications occur only at targeted sites, preserving the integrity and function of the antigen-binding domains.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent introduces enzyme intermediaries (such as transglutaminase, sortase, or O-glycosidase) that facilitate the specific attachment of foreign substances to predetermined amino acid residues. These enzymes act as mediators to enable controlled, site-specific labeling without requiring random collisions, thus maintaining antibody recognition ability while achieving effective labeling.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Manufacturing precision

If site-specific labeling technology is developed through genetic modulation or modification, then the labeling precision is improved, but the technical complexity and cost increase

Engineering Contradiction:
Improvelabeling site specificityVSAvoidantibody modification complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent utilizes the antibody's own structural features, specifically exposed amino acid residues (such as lysine or glutamine) in the Fc region, as natural labeling sites. This approach eliminates the need for genetic modification of the antibody sequence, as the target sites are inherently present in the wild-type antibody structure. The method leverages the antibody's self-structure to enable site-specific labeling, reducing technical complexity and cost.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent changes the chemical parameters of the labeling reaction by using specific enzymes that recognize and modify particular amino acid side chains. Instead of genetic modification, the approach uses enzymatic catalysis to alter the chemical state of specific residues, enabling site-specific labeling through controlled biochemical reactions rather than structural engineering of the antibody gene.

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 uniformity and preserves antibody function, maintaining binding affinity and half-life, enabling site-specific labeling without complex processes.

Implementation Method 1

a peptide having a binding activity for an Fc domain of the antibody and comprising an amino acid sequence represented by general formula (1)

Methodology Applied
Scientific EffectPeptide-antibody binding:

Implementation Method 2

wherein Xa 1 is and D 3 is a covalent bond or C 1‑3 alkylene

Methodology Applied
Scientific EffectNucleophilic addition:

Data Source

PatentEP4711386A2Site-specific antibody conjugation and antibody-drug conjugate as specific example thereof
Publication Date: 2026.03.18 ABTIS CO LTD
  • EP4711386A2 patent drawingFigure 1
  • EP4711386A2 patent drawingFigure 2
  • EP4711386A2 patent drawingFigure 3

AI summary

The present invention relates to technology capable of labeling a certain site of an antibody with a certain number of chemical functional groups or cargo moieties. The present invention may provide an antibody product having high uniformity. The present invention may provide an antibody product whose antibody functions are not degraded. That is, the present invention may provide an antibody product whose antibody binding affinity and half-life are not degraded. The present invention is of great significance as being the first technology allowing site-specific labeling of an antibody without any complicated processes.