Enzyme Encapsulation in an Engineered Lumazine Synthase Protein Cage

Area of Science:

• Biochemistry
• Protein Engineering
• Biotechnology

Background:

• Controlling enzyme activity is crucial for biochemical applications.
• Protein cages offer a promising system for enzyme encapsulation.
• Genetically programmable tags can facilitate targeted protein assembly.

Purpose of the Study:

• To develop a protocol for encapsulating enzymes within engineered protein cages.
• To utilize a positively charged green fluorescent protein (GFP(+36)) tag for efficient enzyme loading.
• To characterize the resulting enzyme-cage inclusion complexes and their catalytic activity.

Main Methods:

• Engineering a negatively charged lumen variant of Aquifex aeolicus lumazine synthase (AaLS-13) cages.
• Creating fusion proteins of enzymes with a positively charged GFP(+36) tag.
• Spontaneous self-assembly of enzyme-loaded cages in aqueous solution.
• Characterization of inclusion complexes and enzyme kinetics.

Main Results:

• Successful rapid and quantitative loading of enzymes into AaLS-13 cages.
• Demonstration of spontaneous cargo localization via electrostatic interactions.
• Detailed protocol provided for cage and fusion protein preparation.
• Discussion of optimal conditions for encapsulation and kinetic assays.

Conclusions:

• The described method provides a robust strategy for enzyme encapsulation in protein cages.
• This technique enables precise control over enzyme activity through packaging.
• The protocol facilitates the development of novel biocatalytic systems.