Rational design of a hexameric protein assembly stabilized by metal chelation
Rafael Alcala-Torano1, Mathieu Walther1, Dayn J Sommer1
1School of Molecular Sciences, Arizona State University, Tempe, Arizona.
Biopolymers
|September 8, 2018
Summary
Researchers created large, stable protein nanostructures using metal-chelating 2,2'-bipyridine (Bpy) units. These self-assembled protein trimers demonstrate controlled organization and thermal stability, paving the way for novel smart materials.
Area of Science:
- Biomaterials Science
- Supramolecular Chemistry
- Protein Engineering
Background:
- Protein-based self-assembled nanostructures offer potential as smart materials.
- Metal chelation provides a strategy for controlling protein module assembly through directional, high-affinity bonding.
Purpose of the Study:
- To utilize 2,2 -bipyridine (Bpy) units to template the assembly of large protein structures.
- To investigate the metal-dependent assembly and properties of these protein constructs.
Main Methods:
- Incorporation of 2,2 -bipyridine units into protein side chains.
- Metal-dependent templated assembly of protein modules into trimers.
- Circular dichroism spectroscopy to analyze helical content and enantiomeric preference.
Main Results:
- Successfully assembled large protein structures (approx. 35,000 Da) via metal-dependent Bpy complexation.
- Structures formed stable trimers of 3-helix bundles, held by 2 Me(Bpy)3 complexes.
- Assemblies exhibited high thermal stability (>90% helical at 90°C) and a preference for one Bpy enantiomer.
Conclusions:
- Protein-based nanostructures can be controllably assembled using Bpy-metal chelation.
- These self-assembled structures possess significant thermal stability.
- The sequence flexibility allows for precise organization of functional groups within supramolecular assemblies.
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