Peptide Beta-1,3-Glucan Complex Bonding

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Solution Overview

Problem

The existing methods for producing ternary complexes of β-1,3-glucan/antigenic peptide/CpG DNA face challenges such as low yield, difficulty in controlling reaction sites due to multiple amino groups in peptides, and cumbersome formation of covalent bonds, leading to issues with immunogenicity and purification.

Innovation Solution

A peptide/β-1,3-glucan complex is developed, where an antigenic peptide is chemically bonded to a polysaccharide with a β-1,3-glucan backbone, utilizing various bonding types including covalent, ionic, hydrogen, and van der Waals bonds, and a polynucleotide derivative with phosphorothioate substitutions, forming a complex with a triple helix structure for enhanced stability and delivery.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If covalent bonding is used to form peptide/β-1,3-glucan complex, then stability of the complex is improved, but the reaction becomes cumbersome and productivity decreases

Engineering Contradiction:
Improvecomplex stabilityVSAvoidproduction yield
Core Design Contradiction:
Stability of the object's compositionVSProductivity

Solution Approach 1:

The patent introduces a carbodiimide compound as an intermediary reagent to mediate the bonding between the carboxyl group of β-1,3-glucan and the amino group of the peptide. This intermediary approach activates the carboxyl group to form an O-acylisourea intermediate, which then reacts with the amino group to form a stable amide bond. This method improves both the stability of the complex and the productivity of the reaction by providing a efficient coupling mechanism that reduces side reactions and simplifies the process.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If multiple amino groups in peptide are used for bonding, then bonding sites increase, but control of reaction site becomes difficult and purification difficulty increases

Engineering Contradiction:
Improvebonding site optionsVSAvoidreaction site control
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent modifies the peptide structure by introducing a protective group at the N-terminal amino group, which prevents this site from participating in the bonding reaction. This local modification ensures that the carboxyl group of β-1,3-glucan bonds specifically to the C-terminal or side-chain amino groups of the peptide, achieving precise control over the reaction site. This approach maintains the versatility of having multiple potential bonding sites while ensuring manufacturing precision through selective protection and deprotection strategies.

Inventive Principle:
Principle #3Local quality

3Strength

If periodate oxidation is used to form formyl group on β-1,3-glucan, then reactivity with peptide amino group is improved, but yield decreases due to low coupling efficiency

Engineering Contradiction:
ImprovereactivityVSAvoidcoupling yield
Core Design Contradiction:
StrengthVSProductivity

Solution Approach 1:

The patent changes the chemical parameters of the β-1,3-glucan by oxidizing it with periodate to introduce formyl groups at the C-6 position of the glucose units. This parameter change dramatically increases the reactivity of the glucan toward peptide amino groups. The oxidation creates multiple aldehyde groups that can undergo reductive amination with amino groups, significantly improving coupling efficiency and yield while maintaining high reactivity.

Inventive Principle:
Principle #35Parameter changes

4Reliability

If ternary complex structure is formed, then immunostimulatory activity is improved, but complexity of production process increases

Engineering Contradiction:
Improveimmunostimulatory activityVSAvoidproduction process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines three components (β-1,3-glucan, peptide antigen, and CpG DNA) into a single ternary complex structure through covalent bonding. The β-1,3-glucan is first oxidized to introduce formyl groups, then the peptide is coupled through reductive amination, and finally CpG DNA is incorporated to form the complete ternary complex. This merging of multiple functional components into one integrated structure achieves high immunostimulatory activity while streamlining the production process into a sequential three-step procedure.

Inventive Principle:
Principle #5Merging (Combining)

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 peptide/β-1,3-glucan complex achieves high yield and immunostimulatory activity, facilitating specific immune responses and broad antigen recognition, making it suitable as a vaccine or immunostimulant with improved productivity and cost-effectiveness.

Implementation Method 1

reacting a carboxyl group of the polysaccharide with an amino group of the antigenic peptide through carbodiimide-mediated coupling

Methodology Applied
Scientific EffectCarbodiimide-mediated coupling: Chemical Bonding

Implementation Method 2

to form a peptide/β-1,3-glucan complex covalently bonded through an amide bond

Methodology Applied
Scientific EffectAmide bond formation: Chemical Bonding

Implementation Method 3

β-1,3-glucan molecules and the nucleic acid molecule in the triple-strand helix complex are considered to form intermolecular bonding mainly through hydrogen bonds

Methodology Applied
Scientific EffectHydrogen bonding: Chemical Bonding

Implementation Method 4

β-1,3-glucan molecules and the nucleic acid molecule in the triple-strand helix complex are considered to form intermolecular bonding mainly through hydrogen bonds and hydrophobic interaction

Methodology Applied
Scientific EffectHydrophobic interaction: Van der Waals Force

Data Source

PatentEP3103807B1Peptide/ beta-1,3-glucan complex and production method therefor, and pharmaceutical composition containing peptide/ beta-1,3-glucan complex
Publication Date: 2021.08.25 THE JAPAN SCI & TECH AGENCY
  • EP3103807B1 patent drawingFigure 1~2
  • EP3103807B1 patent drawingFigure 3~4
  • EP3103807B1 patent drawingFigure 5~6

AI summary

This peptide/β-1,3-glucan complex includes β-1,3-glucan and a peptide/polynucleotide conjugate in which an antigenic peptide is bonded covalently to a polynucleotide or a derivative thereof. The polynucleotide or derivative thereof of the peptide/polynucleotide conjugate bonds via a hydrogen bond with β-1,3-glucan, forming a complex having a triple helix structure including a single molecular chain of the polynucleotide or derivative thereof and two molecular chains of the β-1,3-glucan. Alternatively, the side chain of the β-1,3-glucan and the antigenic peptide are bonded covalently formed by either a cycloaddition reaction between an alkyne and an azide derivative, or a reaction between a maleimide group or a vinyl sulfone group and a thiol group.