Integrin Antagonists Resolving Thrombocytopenia via Inactive State Stabilization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current integrin ligand-mimetic antagonists, such as cyclic RGD-like molecules, induce severe thrombocytopenia and paradoxically cause thrombosis and mortality due to persistent conformational changes in integrins, and RGD-bearing antagonists stimulate tumor growth and angiogenesis.
Innovation Solution
Development of a polypeptide with specific amino acid sequences that stabilize the βA domain in the inactive state of integrins, preventing activation and using these polypeptides in pharmaceutical compositions for treating various disorders.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If cyclic RGD-like molecules are used as integrin antagonists, then thrombosis prevention is improved, but severe thrombocytopenia and mortality are induced
Solution Approach 1:
The patent applies parameter changes by modifying the chemical structure of RGD-based compounds. Specifically, it uses non-peptidic isosteres (structural replacements with similar properties) and bioisosteres to replace peptide bonds and amino acid side chains, transforming the molecule from a peptidic structure to a non-peptidic structure while maintaining integrin binding affinity but eliminating the harmful conformational changes that cause thrombocytopenia
Solution Approach 2:
The patent applies local quality by making specific localized modifications to the RGD motif structure. The core RGD sequence is preserved for integrin binding, but surrounding peptidic structures are replaced with non-peptidic isosteres only in the regions that cause harmful effects, allowing the therapeutic benefit to be maintained while eliminating specific harmful interactions
2Reliability
If RGD-bearing antagonists are used to block integrin activation, then thrombosis is prevented, but paradoxical thrombosis and mortality occur
Solution Approach 1:
The patent converts the harmful conformational changes induced by RGD antagonists into a beneficial outcome by designing molecules that bind to integrins without triggering activation. The non-peptidic isostere structure allows the molecule to occupy the binding site and prevent pathological thrombosis while the specific structural features prevent the inward movement of the N-terminal alpha helix that would otherwise trigger integrin activation and paradoxical thrombosis
Solution Approach 2:
The patent inverts the typical mechanism by which RGD peptides work. Instead of allowing integrin activation followed by blockade, the non-peptidic isostere directly blocks the inactive integrin conformation and prevents activation from occurring in the first place, thereby inverting the sequence of events to avoid paradoxical thrombosis
3Reliability
If RGD-bearing antagonists are used to inhibit integrin binding, then thrombosis is reduced, but tumor growth and angiogenesis are stimulated
Solution Approach 1:
The patent applies local quality by differentiating the effects on different integrin types. The non-peptidic isostere structure is designed to have high selectivity for platelet integrins (αIIbβ3) involved in thrombosis, while having minimal effect on tumor integrins (such as αVβ3). This is achieved through optimized structural features that match the binding pocket geometry of platelet integrins but not tumor integrins
Solution Approach 2:
The patent uses parameter changes in the form of structure-activity relationship optimization. By modifying the non-peptidic isostere parameters (molecular size, shape, charge distribution, and functional group positioning), the compound achieves differential binding affinity: strong binding to platelet integrins for thrombosis prevention, but weak binding to tumor integrins to avoid stimulating tumor growth and angiogenesis
Data Source
AI summary
Provided herein are integrin antagonists and methods of using the same. For example, one or more of the compounds or polypeptides provided herein can be used in the treatment of disorders such as heart attacks, stroke, and cancer metastasis.