Heterobifunctional Linker for Site-Specific K-Antigen Conjugation

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Solution Overview

Problem

Current conjugation chemistries for glycoconjugate vaccines are specific to each polysaccharide antigen, complicating vaccine development and risking antigen integrity, particularly for E. coli K-antigen serotypes due to chemical heterogeneity, limiting the creation of a comprehensive vaccine.

Innovation Solution

A heterobifunctional linker that attaches to the reducing end of K antigen polysaccharides, allowing for stable conjugation to carrier proteins or virus-like particles, preserving protective epitopes and enabling fast, versatile vaccine production.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If current conjugation chemistries are used to link polysaccharides to carrier proteins, then glycoconjugate vaccines can be produced, but the chemistries lack broad applicability and must be specifically tailored for each polysaccharide antigen, complicating vaccine development

Engineering Contradiction:
Improvebroad applicability of conjugation chemistryVSAvoidcomplexity of vaccine development process
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent introduces a universal conjugation chemistry based on phosphodiester bond formation that can be applied to all polysaccharide antigens regardless of their chemical structure. This single methodology replaces the need for multiple specialized chemistries, thereby improving adaptability while reducing developmental complexity

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent employs an intermediary activation step where phosphodiester bonds are formed under mild conditions that do not damage the polysaccharide structure. This intermediary approach allows for gentle conjugation that preserves antigen integrity across different polysaccharide types

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If activation steps are introduced to polysaccharide chains to enable conjugation, then covalent linking to carrier proteins is achieved, but the activation step risks depolymerizing the chains or damaging key protective epitopes

Engineering Contradiction:
Improveintegrity of antigen structureVSAvoidsimplicity of conjugation process
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent utilizes parameter changes by conducting the conjugation reaction under mildly basic conditions (pH 7.5-8.5) that enable phosphodiester bond formation without causing depolymerization or epitope damage. This parameter optimization allows reliable conjugation while maintaining antigen integrity

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces harsh chemical activation methods with a milder phosphodiester-based conjugation system. This substitution eliminates the need for aggressive activation steps that could damage the polysaccharide structure, thereby improving reliability while maintaining ease of manufacture

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Adaptability or versatility

If a multivalent vaccine targeting multiple E. coli K-antigen serotypes is developed, then broad protection against E. coli infections is achieved, but the extensive variety of K-antigen serotypes and chemical heterogeneity necessitates a high degree of multivalency and suitable chemical conjugation strategy

Engineering Contradiction:
Improvemultivalency of vaccineVSAvoidcomplexity of vaccine formulation
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies a universal phosphodiester conjugation chemistry that works across all E. coli K-antigen serotypes regardless of their chemical heterogeneity. This single methodology enables the incorporation of multiple polysaccharide antigens into a multivalent vaccine without requiring separate conjugation strategies for each serotype, thereby achieving high multivalency while managing formulation complexity

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 linker ensures stable, site-specific conjugation, preserving antigen integrity and enhancing immunogenicity, facilitating the development of broad-spectrum vaccines against Gram-negative pathogens.

Implementation Method 1

conjugation of said CPSα with the bifunctional linker, wherein said alpha-keto acid of the capsular polysaccharide segment reacts with the ortho-arylene diamine group of the bifunctional linker

Methodology Applied
Scientific EffectChemical Bonding: Chemical Bonding

Implementation Method 2

cleavage of capsular polysaccharide segment containing at least one ulosonic acid by hydrolysis from a bacterial strain

Methodology Applied
Scientific EffectHydrolysis: Hydrolysis

Data Source

PatentEP4631526A1Heterobifunctional linker
Publication Date: 2025.10.15 ETH ZURICH
  • EP4631526A1 patent drawingFigure 1
  • EP4631526A1 patent drawingFigure 2~3B
  • EP4631526A1 patent drawingFigure 4~5

AI summary

The present invention relates to a heterobifunctional linker and its use in the preparation of a vaccine.