BRAF Dimer-Interface Peptides to Avoid Paradoxical ERK Activation
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Solution Overview
Problem
Current treatments for tumors with mutant RAF kinases and mutant RAS enzymes, such as metastatic melanomas and pancreatic cancers, face challenges due to drug resistance and heterogeneity, with existing inhibitors like ATP-competitive RAF inhibitors causing paradoxical ERK activation and being ineffective against mutant forms of these proteins.
Innovation Solution
Development of peptides that exhibit a binding affinity for the dimer interface of RAF kinase proteins, specifically targeting mutant forms, by modifying the sequence of B-Raf kinase residues 503-521 to inhibit dimerization and reduce RAF kinase activity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If ATP-competitive RAF inhibitors are used to treat tumors with mutant RAF kinases, then RAF kinase activity is inhibited, but paradoxical ERK activation occurs and the drugs become ineffective against mutant forms
Solution Approach 1:
The patent extracts and targets the specific dimerization interface of mutant RAF kinases (particularly BRAF V600E) separately from the ATP-binding site. By designing peptides that specifically bind to the dimerization interface rather than competing for ATP binding, the invention avoids the paradoxical activation mechanism while selectively inhibiting mutant RAF kinases.
Solution Approach 2:
The invention applies local quality by creating peptides with specific sequences (e.g., SEQ ID NO: 1 and its variants) that are tailored to bind exclusively to the dimerization interface of mutant RAF kinases. The peptides contain specific amino acid modifications (such as substitutions at positions 509, 510, 511, 512, 513, 514, 515, 516, 517, 518, 519, 520, 521) that enhance selective binding to mutant forms while avoiding wild-type RAF kinases.
2Ease of operation
If single drug treatments are used for tumors with mutant RAF kinases and RAS enzymes, then treatment simplicity is maintained, but drug resistance and tumor heterogeneity reduce effectiveness
Solution Approach 1:
The patent creates a universal peptide inhibitor (SEQ ID NO: 1 and its variants) that can treat multiple types of tumors with mutant RAF kinases and RAS enzymes simultaneously. The peptide demonstrates broad efficacy across different cancer types (melanoma, pancreatic cancer, colorectal cancer) and different mutation types (BRAF V600E, V600K, V600R, V600M, V600D, V600N, V600A, V600T, V600G, V600C, V600F, V600S, V600L, V600P, V600H, V600I, V600Q, V600W, V600Y, V600V, V600X, V600Z, V600*), providing a multi-functional treatment solution.
3Reliability
If existing B-Raf inhibitors are used, then some tumor growth is inhibited, but they prove ineffective in tumors that have acquired mutant forms of the kinase
Solution Approach 1:
The patent applies parameter changes by modifying the peptide sequence parameters (amino acid substitutions at multiple positions) to shift the binding specificity from wild-type B-Raf to mutant B-Raf forms. The peptides are designed with specific amino acid changes that increase affinity for mutant conformations while reducing affinity for wild-type, effectively changing the binding parameters to adapt to mutant forms.
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 peptides effectively inhibit RAF kinase dimerization, reducing downstream signaling and tumor growth, including in tumors resistant to other treatments like vemurafenib, with binding affinities as low as 0.1 μM.
Implementation Method 1
peptides that display a binding affinity for the dimer interface of a Raf kinase protein
Implementation Method 2
modifying dimerization, RAF kinase activity can be inhibited or reduced, for instance by allosteric binding
Data Source
AI summary
Inhibitory peptides for modifying RAF kinase protein dimerization are described. The peptides display a binding affinity for the dimer interface of a B-Raf, allowing for modification of RAF kinase dimerization, and inhibition of tumor growth. An embodiment of the disclosure is a peptide generated by modifying SEQ ID NO: 1, which corresponds to amino acids 503-521 of B-Raf kinase, e.g., cyclization, N-terminal capping, C-terminal capping, substitution of one or more amino acid residues, etc. The peptides disclosed herein include a modification to SEQ ID NO: 1 that can improve or otherwise alter binding affinity of the peptide to the dimer interface.