Cyclic Polypeptides for Restoring Mutant ENaC Sodium Transport
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Solution Overview
Problem
Current treatments for autosomal recessive pseudohypoaldosteronism type 1 (PHA type 1B) are limited to fluid and electrolyte management, with no drug-based therapy available to restore or increase the sodium ion transport capacity of mutant loss-of-function epithelial sodium channels (ENaC) in patients, leading to severe salt-wasting and life-threatening complications.
Innovation Solution
Development of cyclic polypeptides, such as AP301 and AP318, which are designed to restore the sodium ion transport capacity of mutant ENaC by mimicking the lectin-like domain of TNF-alpha and forming a cyclic structure through disulfide bridges or amide bonds, enhancing ENaC function.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If fluid and electrolyte management is used for treatment, then salt-wasting and electrolyte imbalances can be managed, but no restoration of sodium ion transport capacity occurs and aggressive salt replacement is required
Solution Approach 1:
The patent introduces cyclic polypeptides as intermediary substances that bind to mutant ENaC channels and restore their function. These polypeptides act as mediators between the mutant channel and normal physiological function, enabling sodium transport restoration without direct genetic correction or complex multi-drug regimens
2Reliability
If aggressive salt replacement is used to manage electrolyte imbalance, then survival is ensured, but the underlying transport defect remains untreated and high salt intake is required
Solution Approach 1:
The cyclic polypeptides enable the mutant ENaC channels to restore their own function without external salt supplementation. The polypeptides bind to the mutant channels and facilitate their proper folding and activation, allowing the system to self-correct the transport defect and maintain electrolyte balance through normal physiological mechanisms
3Ease of operation
If no drug-based therapy is available, then current treatments are limited to supportive care, but restoration of ENaC function cannot be achieved
Solution Approach 1:
The cyclic polypeptides are designed to mimic the lectin-like domain of TNF-alpha, which naturally binds to and activates ENaC channels. By copying the functional domain of this natural ligand, the patent creates a simplified therapeutic agent that can restore ENaC function without requiring complex protein structures or multiple drug components
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 cyclic polypeptides effectively restore the sodium ion transport capacity of mutant ENaC to physiological levels, compensating for amino acid mutations and improving salt balance in PHA type 1B patients, reducing the need for aggressive salt replacement and managing electrolyte imbalances.
Implementation Method 1
forming a cyclic structure through disulfide bridges or amide bonds
Implementation Method 2
designed to restore the sodium ion transport capacity of mutant ENaC by mimicking the lectin-like domain of TNF-alpha
Data Source
AI summary
A cyclic polypeptide comprising at least six contiguous amino acids from the amino acid sequence SEQ ID NO: 1 Gly-Gln-Arg-Glu-Thr-Pro-Glu-Gly-Ala-Glu-Ala-Lys-Pro-Trp-Tyr for the treatment of autosomal recessive pseudohypoaldosteronism type 1 (PHA type1B) or for the restoration of the Na+ transport capacity of mutated loss-of-function ENaC.