Peptide Variants for Integrin AlphaVbeta6 Targeting
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Solution Overview
Problem
Current peptide therapies targeting integrin αvβ6 face limitations due to short half-life in blood caused by susceptibility to serum proteases, necessitating enhanced binding activity, cellular uptake, and extended plasma half-life for effective tumor targeting and imaging.
Innovation Solution
Development of A20FMDV2 peptide variants with specific amino acid sequences and modifications, such as D-Asn at the N-terminus and L-Thr or D-Thr at the C-terminus, which exhibit enhanced binding activity and bio-distribution to αvβ6-expressing tumors, along with conjugation to therapeutic or detectable moieties for improved stability and delivery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If A20FMDV2 peptide is used for tumor targeting, then binding activity to integrin αvβ6 is achieved, but plasma half-life is short due to susceptibility to serum proteases
Solution Approach 1:
The patent applies parameter changes by substituting specific amino acid residues in the A20FMDV2 peptide sequence with chemically modified residues. Specifically, the N-terminal alanine is replaced with D-Asn, and the C-terminal valine is replaced with L-Thr or D-Thr. These parameter changes in the peptide structure enhance resistance to serum proteases while maintaining or improving binding activity to integrin αvβ6, thereby extending plasma half-life.
2Duration of action of moving object
If peptide sequence is modified to improve stability, then plasma half-life is extended, but binding activity may be reduced
Solution Approach 1:
The patent carefully selects specific amino acid positions for modification (N-terminal alanine and C-terminal valine) while preserving the critical RGD motif and other binding-important residues. The substitutions with D-Asn and L-Thr/D-Thr are chosen to provide steric and electronic properties that enhance protease resistance without significantly disrupting integrin αvβ6 binding, thus resolving the contradiction between stability and binding activity.
3Duration of action of moving object
If PEGylation is applied to extend half-life, then plasma stability is improved, but device complexity increases
Solution Approach 1:
The patent applies local quality by making targeted, localized modifications only at specific positions (N-terminal and C-terminal residues) rather than applying PEGylation throughout the entire peptide. This localized approach provides protease resistance with minimal structural changes, avoiding the complexity of PEG conjugation while achieving the desired extension of plasma half-life.
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 variants demonstrate superior binding activity, cellular uptake, and plasma stability, enabling selective targeting and retention in αvβ6-expressing tumors, potentially enhancing therapeutic delivery and imaging efficacy.
Implementation Method 1
A peptide that selectively binds integrin αvβ6, wherein the peptide has an amino acid sequence comprising the motif XBnRGDLX2X3X4ZmX5
Implementation Method 2
enhanced cellular uptake as compared with A20FMDV2 peptide
Implementation Method 3
conjugated to a detectable moiety... detectable by Magnetic Resonance Imaging (MRI), Magnetic Resonance Spectroscopy (MRS), Single Photon Emission Computed Tomography (SPECT), Positron Emission Tomography (PET) or optical imaging
Implementation Method 4
assessed by 111In-labelling
Data Source
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AI summary
The present invention provides a peptide that selectively binds ανβ6 integrin, the peptide having an amino acid sequence comprising the motif X1BnRGDLX2X3X4 ZmX5, wherein X1 is any D-amino acid, Bn is a sequence of any n amino acids, which may be natural or unnatural, D- or L-, and may be the same or different, wherein n is a number between 1 and 10, X2 and X3 are independently selected from any amino acid, X4 is Leu or Ile, Zm is a sequence of any m amino acids, which may be natural or unnatural, D- or L-, and may be the same or different, wherein m is a number between 1 and 10, X5 is any L- or D-amino acid. Also provided are conjugates comprising said peptide, pharmaceutical compositions comprising said peptide or said conjugates, and uses of said peptide, conjugate or composition, for example, in the treatment, imaging and/or diagnosis of an ανβ6- expressing tumour in a mammalian subject.