Opsin-Binding Ligands for Protein Folding Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current treatments for ophthalmic diseases such as retinitis pigmentosa and age-related macular degeneration are limited by the toxicity of visual cycle products like all-trans-retinal and A2E, which can cause photoreceptor cell death and vision loss, especially during surgical procedures, due to improper protein folding and trafficking of opsin proteins.
Innovation Solution
Development of small molecule ligands that non-covalently bind to opsin proteins, inhibiting the binding of 11-cis-retinal and promoting proper folding and trafficking, thereby reducing the formation of toxic visual cycle products and preventing photoreceptor cell death.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If chemical chaperones (e.g., glycerol, trimethylamine oxide) are used to stabilize misfolded opsin proteins, then protein folding is improved, but toxic side effects occur due to high dosages required
Solution Approach 1:
The patent uses specific retinoid compounds as intermediary molecules that selectively bind to misfolded opsin proteins, acting as pharmacological chaperones. These retinoids serve as mediators between the misfolded protein and the cellular quality control mechanisms, promoting proper folding and trafficking without requiring high concentrations that would cause systemic toxicity.
Solution Approach 2:
The invention changes the chemical parameters by using specific retinoid derivatives with optimized binding affinity and selectivity. By modifying the chemical structure of retinoids (e.g., using compounds like 9-cis-retinal, retinol, or synthetic analogs), the patent achieves effective stabilization at low concentrations, thereby reducing toxic side effects while maintaining protein folding stability.
2Stability of the object's composition
If retinoid compounds are used as pharmacological chaperones to stabilize mutant opsin proteins, then protein stability is improved, but interference with the visual cycle occurs
Solution Approach 1:
The patent applies local quality by designing retinoid compounds that selectively interact with misfolded opsin proteins at specific binding sites, particularly in the endoplasmic reticulum and Golgi apparatus. This localized action stabilizes mutant opsins without interfering with the normal visual cycle processes that occur in the rod outer segments, where 11-cis-retinal binding and phototransduction take place.
Solution Approach 2:
The invention segments the action of retinoids by using compounds that preferentially bind to misfolded proteins in specific cellular compartments (ER, Golgi) rather than uniformly binding to all opsin molecules throughout the cell. This segmentation allows stabilization of mutant proteins in the secretory pathway while leaving functional opsin-rhodopsin complexes in the photoreceptor outer segments unaffected.
3Object-affected harmful factors
If small molecule ligands bind to opsin proteins to inhibit 11-cis-retinal binding, then toxic visual cycle product formation is reduced, but rhodopsin formation is inhibited
Solution Approach 1:
The patent applies preliminary anti-action by using small molecule ligands that preemptively bind to misfolded opsin proteins in the endoplasmic reticulum and Golgi, preventing their aggregation and promoting proper folding before they can form toxic aggregates. This preliminary stabilization occurs upstream in the secretory pathway, allowing normal 11-cis-retinal binding and rhodopsin formation to proceed in properly folded proteins that reach the photoreceptor outer segments.
Solution Approach 2:
The invention uses small molecule ligands as intermediaries that temporarily bind to misfolded opsin proteins to correct their conformation, then dissociate to allow normal visual cycle function. These intermediary molecules facilitate proper protein folding without permanently blocking the retinal binding site, enabling both protein stabilization and normal rhodopsin formation in corrected proteins.
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 small molecule ligands effectively reduce the formation of toxic visual cycle products, inhibit excessive rhodopsin activation, and promote correct opsin protein processing, thereby preventing photoreceptor cell death and vision loss in ophthalmic diseases.
Implementation Method 1
small molecule ligands that non-covalently bind to opsin proteins, inhibiting the binding of 11-cis-retinal and promoting proper folding and trafficking
Implementation Method 2
contacting the mislocalized opsin protein with an agent that binds reversibly and/or non-covalently to the mislocalized opsin protein, thereby inhibiting the binding of 11-cis-retinal to the opsin protein
Data Source
Figure 1
AI summary
Compounds are disclosed that are useful for treating ophthalmic conditions caused by or related to production of toxic visual cycle products that accumulate in the eye, such as dry adult macular degeneration, as well as conditions caused by or related to the misfolding of mutant opsin proteins and/or the mis-localization of opsin proteins. Compositions of these compounds alone or in combination with other therapeutic agents are also described, along with therapeutic methods of using such compounds and/or compositions. Methods of synthesizing such agents are also disclosed.