Unnaturally Distorted Hexagonal Protein Ring Alternatingly Reorganized from Two Distinct Chemically Modified Proteins

Area of Science:

• Biochemistry
• Structural Biology
• Synthetic Biology

Background:

• Natural protein assemblies exhibit specific structures and functions.
• Modifying protein interfaces is challenging using conventional methods.

Purpose of the Study:

• To construct a semiartificial protein assembly with altered symmetry.
• To explore the utility of chemical modification for protein engineering.

Main Methods:

• Scrap-and-build approach using chemical modification.
• Design of two dimeric mutants based on peroxiredoxin.
• Reorganization of dimers into a ring using synthetic naphthalene moieties.
• Cryo-electron microscopy for structural analysis.

Main Results:

• Formation of a uniquely shaped dodecameric hexagonal protein ring with broken symmetry.
• Artificial naphthalene moieties introduced at dimer interfaces.
• Establishment of distinct, including unnatural, protein-protein interactions.
• Demonstration of a novel protein assembly inaccessible by standard mutations.

Conclusions:

• Chemical modification is a powerful technique for creating semiartificial protein structures.
• This method allows access to protein assemblies with unique architectures and properties.
• The study expands the possibilities of protein engineering beyond amino acid substitutions.