C5a Agonist Hydrochloride Salts for Selective APC Activation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing C5a receptor agonists and antagonists fail to differentiate between C5a receptors on macrophages and granulocytes, leading to non-specific inflammatory responses and limited efficacy in treating inflammatory disorders.
Innovation Solution
Development of hydrochloride (HCl) salt forms of C-terminal C5a analogs, such as EP67, which selectively bind and activate C5a receptor-bearing APCs, avoiding pro-inflammatory activities, and are conformationally stable to enhance immune response specificity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional C5a receptor agonists are used, then immune response is activated, but non-specific inflammatory responses occur due to inability to differentiate between macrophage and granulocyte receptors
Solution Approach 1:
The patent modifies specific local regions of the C5a peptide structure (N-terminal and C-terminal regions) to create differential binding affinity. By altering local amino acid sequences and adding specific salt forms, the agonist achieves selective interaction with C5aR on macrophages while avoiding binding to C5aR on granulocytes, thus resolving the non-specific inflammatory response issue
Solution Approach 2:
The patent changes physical-chemical parameters of the C5a analog including salt form selection (hydrochloride, trifluoroacetate, acetate), peptide sequence modifications, and conformational constraints. These parameter changes enable selective activation of macrophage C5aR while preventing activation of granulocyte C5aR, achieving specific immune response without non-specific inflammation
2Reliability
If C5a analogs are designed for selective binding, then receptor specificity improves, but peptide conformational stability decreases
Solution Approach 1:
The patent incorporates conformational constraints and stabilizing modifications into the peptide structure during synthesis. By pre-establishing stable conformations through disulfide bridges, cyclic structures, or specific amino acid substitutions, the analog maintains both selective binding capability and structural stability in physiological conditions
Solution Approach 2:
The patent creates composite peptide structures combining rigid conformational elements with flexible binding regions. This composite design allows the peptide to maintain a stable overall structure while preserving the flexibility needed for specific receptor recognition, thus achieving both conformational stability and binding specificity
3Quantity of substance
If conventional salt forms are used, then peptide solubility is maintained, but immune-enhancing potency and acquisition speed are reduced
Solution Approach 1:
The patent systematically evaluates and selects optimal salt forms (hydrochloride, trifluoroacetate, acetate) based on their impact on peptide solubility, stability, and biological activity. The hydrochloride salt form is identified as providing the optimal balance of solubility and rapid immune response acquisition, enabling faster potency development while maintaining adequate solubility
Data Source
AI summary
Hydrochloride salt forms of synthetic C-terminal peptide analogs of C5a, which are response selective agonists of C5aR-bearing antigen presenting cells. Methods of inducing an immune response in a subject by administering such peptide analogs alone or in combination with other active agents are also disclosed.