MAXCAP Peptide Agonists for Selective PAC1 Receptor Activation
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Solution Overview
Problem
Current treatments for conditions such as obesity, type 2 diabetes, and liver diseases lack effective agents that specifically target PAC1 receptors to regulate appetite, body metabolism, and liver steatosis without significant side effects.
Innovation Solution
Development of novel PAC1 receptor agonists, MAXCAPs, which are designed to bind specifically to PAC1 receptors, utilizing key amino acid residues from PACAP and maxadilan peptides, enhancing their affinity and resistance to DPP-IV protease degradation, thereby activating PAC1 signaling pathways.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If PACAP peptides are used to bind PAC1 receptors, then receptor activation is achieved, but the peptides are rapidly degraded by DPP-IV protease with short half-life
Solution Approach 1:
The patent extracts the critical binding motif from PACAP peptides (residues 1-13: HSDGIFTDSYSSRYRKQMAVKKYLAAVL) and separates it from the DPP-IV degradation-sensitive C-terminal portion. By using only the N-terminal fragment that contains the PAC1 receptor binding site, the invention eliminates the vulnerability to proteolytic degradation while maintaining receptor activation capability.
Solution Approach 2:
The patent segments the PACAP peptide into functional regions: the N-terminal fragment (residues 1-13) that provides PAC1 receptor binding activity, and the C-terminal portion that is susceptible to DPP-IV degradation. This segmentation allows the invention to use only the essential binding fragment, thereby extending half-life while preserving receptor activation.
2Reliability
If full-length PACAP peptides are used, then PAC1 receptor binding is achieved, but they also activate VPAC1 and VPAC2 receptors causing off-target effects
Solution Approach 1:
The patent extracts and uses only the N-terminal fragment (residues 1-13) of PACAP that is sufficient for PAC1 receptor binding. This fragment lacks the C-terminal sequences that are responsible for activating VPAC1 and VPAC2 receptors, thereby achieving selective PAC1 receptor activation without off-target effects.
Solution Approach 2:
The patent applies local quality by using a truncated peptide fragment that has different binding characteristics compared to the full-length peptide. The N-terminal fragment (residues 1-13) provides high affinity binding to PAC1 receptor while lacking the structural elements needed for VPAC receptor activation, thus creating a peptide with selective local functionality.
3Adaptability or versatility
If natural PACAP sequences are used, then physiological activity is maintained, but they lack resistance to proteolytic degradation
Solution Approach 1:
The patent extracts the PAC1 receptor binding motif from the natural PACAP sequence and uses it as a standalone fragment. This extracted fragment maintains the physiological activity of PACAP at PAC1 receptors while being inherently resistant to DPP-IV degradation because it lacks the C-terminal sequences that are targets for proteolytic cleavage.
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 MAXCAPs effectively suppress appetite, reduce body fat, improve metabolic syndromes, and alleviate liver steatosis, non-alcoholic fatty liver disease, and insulin resistance, offering a targeted therapeutic approach with potential for long-term efficacy.
Implementation Method 1
novel PAC1 receptor agonists, MAXCAPs, which are designed to bind specifically to PAC1 receptors, utilizing key amino acid residues from PACAP and maxadilan peptides
Implementation Method 2
enhancing their affinity and resistance to DPP-IV protease degradation
Data Source
AI summary
In certain embodiments novel PAC1 receptor agonists are provided wherein the agonists comprise a targeting sequence that binds to the PAC1 receptor and said targeting sequence is attached to an amino acid sequence comprising a fragment of the maxadilan amino acid sequence, wherein the targeting sequence comprises a full-length 38 amino acid PACAP peptide or an N-terminus fragment thereof containing the amino acid sequence HSDGIF, wherein said targeting sequence optionally comprises an amino acid insertion between residues 11 and 12 of said PACAP peptide or fragment thereof; and the fragment of the maxadilan amino acid sequence comprises a fragment of the maxadilan sequence effective to activate PAC1 signaling.