Antagonist Peptide Sequence for CD47 Binding Inhibition
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Solution Overview
Problem
Current strategies for inhibiting the interaction between thrombospondin proteins and the CD47 receptor, such as using monoclonal antibodies, are not specific enough and can interfere with other cellular processes, and existing peptides do not effectively promote apoptosis in cancer cells.
Innovation Solution
A specific antagonist peptide with the sequence XXXSQLLKGXXX, where X denotes certain amino acids, specifically binds to the CD47 receptor's binding site on thrombospondin proteins, preventing their interaction while allowing other natural ligands to bind, thereby inhibiting the anti-apoptotic effect on cancer cells.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If monoclonal antibodies are used to inhibit the interaction between thrombospondin and CD47, then the binding between TSP and CD47 is prevented, but the antibodies are not specific enough and interfere with other cellular processes
Solution Approach 1:
The invention extracts and utilizes only the critical binding interface region of the thrombospondin protein (specifically the C-terminal domain containing the CD47-binding motif). By designing a peptide that mimics only this essential binding region rather than the entire protein structure, the solution achieves specific inhibition of the TSP-CD47 interaction while minimizing interference with other cellular processes that may involve other domains of the full thrombospondin protein.
Solution Approach 2:
The invention applies local quality by creating a peptide that specifically targets and mimics only the local binding interface (the C-terminal domain with the CD47-binding motif) rather than the entire thrombospondin protein. This localized approach ensures that only the specific TSP-CD47 interaction is inhibited, while other functional domains of thrombospondin remain intact and can perform their natural cellular functions.
2Reliability
If existing peptides are used to inhibit TSP-CD47 interaction, then binding is reduced, but they do not effectively promote apoptosis in cancer cells
Solution Approach 1:
The invention applies parameter changes by optimizing the peptide sequence to include not only the CD47-binding motif but also adjacent amino acid residues from the C-terminal domain of thrombospondin. This sequence optimization (changing the structural and chemical parameters of the peptide) enhances both the binding affinity to CD47 and the biological activity required to promote apoptosis in cancer cells, thereby simultaneously improving both binding inhibition and therapeutic effectiveness.
3Reliability
If the entire thrombospondin protein is used to inhibit CD47, then binding is prevented, but the molecule is too large and affects other ligand interactions
Solution Approach 1:
The invention applies segmentation by dividing the thrombospondin protein into functional domains and isolating only the critical C-terminal segment that contains the CD47-binding motif. This segmented approach creates a smaller peptide fragment (amino acids 456-473) that specifically inhibits CD47 binding without the bulk of the rest of the thrombospondin protein, thereby reducing molecular complexity and minimizing interference with other ligand interactions that may occur at other domains.
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 peptide effectively inhibits the binding of CD47 with TSP1 and TSP2, promoting apoptosis in cancer cells by specifically targeting the interaction site, improving bioavailability and reducing immunogenicity, and has shown efficacy in treating various types of cancer, including thyroid, breast, and melanoma.
Implementation Method 1
the peptide interacts specifically with the C-terminal end of the TSP, at the binding site between the TSP and said CD47 receptor, so as to prevent an interaction between said CD47 receptor and said protein
Data Source
AI summary
Antagonist peptide of the bond between CD47 and a protein belonging to the thrombospondin family has the sequence S1 R1-R2-R3-S-Q-L-L-K-G-R4-R5-R6 and interacts specifically with the C-terminal end of the TSP, at the site of the bond between the TSP and the CD47 receptor. Interaction between the CD47 receptor and the protein is prevented. The peptide can be used in the context of cancer treatments.