Soluble Chelator Design for EDTA-Resistant Protein Binding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing chelators, such as NTA and EDTA, exhibit weak binding affinity and are easily disrupted by common reagents used in protein purification, leading to loss of metal ions and reduced protein binding capacity, especially during multiple washing steps and gel electrophoresis.
Innovation Solution
Development of soluble chelators with aminopolycarboxylic acids, such as EDTA, that form strong, stable complexes with metal ions like Ni, Cu, and Co, resisting interference from EDTA and DTT, allowing for high-affinity binding and selective protein interaction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If standard chelators like NTA are used for protein purification, then protein binding is enabled, but the binding is weak and lost under stress during washing steps and gel electrophoresis
Solution Approach 1:
The patent modifies the NTA chelator structure by replacing the amine nitrogen with an isoniile group (C=N-), creating NiNTA. This chemical parameter change increases the denticity and binding strength of the chelator, enabling stable protein binding that withstands washing steps and gel electrophoresis stress while maintaining selective affinity for His-tagged proteins
2Reliability
If strong chelators like EDTA are used to stabilize metal ions, then metal ion retention is improved, but they compete with the chelator needed for protein binding functions
Solution Approach 1:
The patent creates a chelator system where NiNTA provides localized strong metal ion binding at the purification matrix, while allowing controlled exchange with His-tagged proteins. The isoniile-modified structure creates a unique binding environment that retains metal ions firmly yet permits selective protein interaction, unlike EDTA which creates uniform strong binding that prevents protein access
3Reliability
If DTT is added to stabilize protein SH groups, then protein stability is improved, but it reduces metal ions to uncharged state, lowering protein binding affinity
Solution Approach 1:
The patent employs NiNTA chelator that forms such stable metal ion complexes that they resist reduction by DTT. The isoniile modification creates a more robust metal-chelator bond that prevents DTT from reducing Ni2+ to uncharged nickel, thereby maintaining binding affinity even in the presence of DTT that stabilizes protein thiols
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 new chelators maintain strong protein binding even in the presence of EDTA and DTT, enabling effective protein purification, labeling, and expression control, with high resistance to detergents and reagents, and selective binding of His-tagged proteins and single-stranded nucleic acids.
Implementation Method 1
Chelation is a type of bonding of ions and molecules to metal ions. It involves the formation or presence of two or more separate coordinate bonds between a polydentate (multiple bonded) ligand and a single central atom.
Implementation Method 2
The polyhistidine-tags is able to bind to metal ions and, thus, enables the binding of chelator to the tag.
Data Source
AI summary
The present invention relates to soluble chelator-compounds, methods for their production and their use for the modification and/or immobilization of target molecules.