Alpha-1-Microglobulin Muteins for Expanded Target Binding
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Solution Overview
Problem
There is a need for the generation of lipocalin muteins with alternative binding sites and scaffolds to expand the spectrum of clinical targets, as existing methods rely heavily on immunoglobulins and lack dedicated physiological ligands for lipocalins like α1-microglobulin, hindering the development of muteins with specific binding affinities for new targets.
Innovation Solution
The structural elucidation of human α1m lipocalin is used to create a collection of muteins with altered amino acid sequences in specific loops, allowing them to bind targets other than those bound by wild-type α1m, including the creation of muteins with multiple binding sites and enhanced affinity for specific ligands like Colchicine and Lutetium (177Lu) DOTA-TATE.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If immunoglobulins are used as binding proteins, then binding functionality is achieved, but versatility and adaptability for different targets are limited
Solution Approach 1:
The patent creates a family of lipocalin muteins that can bind to multiple different targets including retinol, fatty acids, and various synthetic ligands. By engineering the lipocalin scaffold to accommodate diverse binding partners, the system achieves multi-functionality and expands the range of applicable targets beyond what single protein classes can provide.
Solution Approach 2:
The patent systematically varies amino acid sequences in the lipocalin muteins, particularly in loop regions, to modify binding specificity and affinity. By changing parameters such as hydrophobicity, charge, and steric properties of residues in the binding pocket, the muteins can be tuned to recognize different target molecules while maintaining the core lipocalin structure.
2Reliability
If wild-type α1m is used, then natural ligand binding occurs, but affinity for alternative clinical targets is insufficient
Solution Approach 1:
The patent introduces site-specific mutations in the lipocalin muteins, particularly in the loop regions that form the binding pocket. By locally modifying amino acid properties at specific positions while maintaining the overall protein structure, the muteins achieve enhanced and selective binding to alternative targets such as colchicine and lutetium-DOTA-TATE, rather than relying on natural ligand binding.
Solution Approach 2:
The patent systematically alters amino acid parameters including hydrophobicity, polarity, and steric bulk at key binding site positions. These parameter changes enable the lipocalin muteins to transition from binding natural ligands like retinol to binding alternative clinical targets with high affinity, expanding the target binding range while maintaining reliable specific interactions.
3Reliability
If lipocalin muteins with altered sequences are created, then binding affinity for new targets is enhanced, but production complexity increases
Solution Approach 1:
The patent optimizes the amino acid sequence parameters of lipocalin muteins to achieve high binding affinity for target molecules such as colchicine and lutetium-DOTA-TATE. By carefully selecting mutations that maximize binding interactions while maintaining protein stability, the muteins achieve reliable high-affinity binding that can be produced through standardized recombinant expression methods.
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
This approach enables the production of lipocalin muteins with specific binding affinities for diverse targets, expanding their clinical applications and providing new tools for biotechnology and medicine by overcoming the limitations of existing lipocalin muteins.
Implementation Method 1
Proteins that selectively bind to selected targets by way of non-covalent interaction play a crucial role as reagents in biotechnology, medicine, bioanalytics
Data Source
AI summary
The present disclosure relates to a collection of novel muteins derived from human α1m (or a1m) polypeptide or a functional homologue thereof. The disclosure further refers to a α1m mutein capable of specifically binding to one or more targets other than a target to which wild-type α1m binds. The disclosure also relates to a method for producing such collection of muteins and a method for isolating a mutein capable of binding one or more such non-natural targets of wild-type α1m polypeptide. These aspects are made possible due to, e.g, the structural elucidation of α1m disclosed herein by the present inventors, an appreciation of ligand-binding sights thereof and, hence, an understanding of which amino acid positions are most suitable for mutagenesis for re-engineering specificity and affinity for any given target while maintaining the secondary and/or tertiary structure of a1m.