Covalent bicyclization of protein complexes yields durable quaternary structures

Area of Science:

• Biochemistry
• Protein Engineering
• Biotechnology

Background:

• Proteins are crucial biomolecules for biotechnological applications, often requiring higher-order structures for function.
• Protein integrity is compromised under application conditions, leading to disassembly, aggregation, and loss of function.
• Stabilizing quaternary protein structures, especially trimers and larger complexes, is challenging due to complex interaction networks.

Purpose of the Study:

• To develop a novel strategy for stabilizing protein quaternary structures.
• To enhance protein resistance to thermal and chemical stress.
• To create proteins with improved stability and shelf life for biotechnological use.

Main Methods:

• Chemical bicyclization of homotrimeric protein complexes.
• Structure-based selection and modification of cross-linking sites to cysteine.
• Reaction with a triselectrophilic agent to form bicyclic protein assemblies.

Main Results:

• Achieved increased protein resistance toward thermal and chemical stress.
• Observed significant resistance toward protein aggregation.
• Demonstrated greatly prolonged shelf life of the modified protein complexes.
• Created proteins with unprecedented bicyclic chain topologies.

Conclusions:

• Chemical bicyclization is an effective strategy for stabilizing protein quaternary structures.
• This method enhances protein stability, prevents aggregation, and extends shelf life.
• The bicyclization approach offers potential for new biotechnological and biomedical applications.