hNGAL Muteins for High-Affinity Small Molecule Binding
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Solution Overview
Problem
Current proteins used for binding and detection of small molecules, such as metal-chelate complexes, face challenges with long circulation times and limited tumor specificity in nuclear medicine, necessitating the development of a small, metal-chelate-specific binding protein with robust folding properties for improved diagnostic and therapeutic applications.
Innovation Solution
Generation of muteins of human neutrophil gelatinase-associated lipocalin (hNGAL) with specific amino acid substitutions at defined sequence positions, enabling high-affinity binding to small molecules like metal-chelating agents with dissociation constants of 200 nM or lower, and potential fusion with targeting peptides or proteins for enhanced specificity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional proteins are used for binding small molecules in nuclear medicine, then binding capability is achieved, but circulation time is prolonged and tumor specificity is limited
Solution Approach 1:
The patent applies parameter changes by creating muteins with specific amino acid substitutions at defined positions (33, 36, 41, 52, 54, 68, 70, 79, 81, 134, 136, 138) to optimize binding affinity for small molecules while controlling circulation characteristics. The mutations are designed to achieve KD ≤ 200 nM for target binding while improving pharmacokinetic properties.
Solution Approach 2:
The patent applies local quality by making specific localized mutations at particular amino acid positions within the hNGAL protein structure. Each position (33, 36, 41, 52, 54, 68, 70, 79, 81, 134, 136, 138) is mutated independently or in combination to fine-tune binding characteristics and circulation time, creating localized functional optimization without affecting the entire protein structure.
2Reliability
If conventional proteins are used for binding small molecules, then binding function is provided, but tumor targeting specificity is insufficient
Solution Approach 1:
The patent uses parameter changes by systematically mutating amino acids at specific positions to create variants with optimized binding affinity for tumor-related small molecules. The mutations are designed to achieve high affinity (KD ≤ 200 nM) for tumor-specific targets while maintaining or improving tumor targeting specificity through careful selection of mutant residues.
Solution Approach 2:
The patent applies segmentation by dividing the protein sequence into specific mutagenesis positions (33, 36, 41, 52, 54, 68, 70, 79, 81, 134, 136, 138) that can be independently optimized. This allows targeted modification of specific regions responsible for binding different tumor markers, enabling multi-specificity or enhanced tumor targeting capability.
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 hNGAL muteins demonstrate improved binding affinity and specificity for small molecules, potentially addressing the limitations of long circulation times and limited tumor targeting in nuclear medicine, enabling more effective diagnostic and therapeutic applications.
Implementation Method 1
Proteins that selectively bind to their corresponding targets by way of non-covalent interaction play a crucial role as reagents in biotechnology, medicine, bioanalytics as well as in the biological and life sciences in general.
Data Source
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AI summary
The present invention relates to novel muteins derived from human lipocalin 2 (hNGAL) and related proteins that bind a given non-natural ligand with detectable affinity. The invention also relates to corresponding nucleic acid molecules encoding such a mutein and to a method for their generation. The invention further relates a method for producing such a mutein. Furthermore, the invention is directed to a pharmaceutical composition comprising such a lipocalin mutein as well as to various uses of the mutein.