Three-Dimensional Protein Cage Array Capable of Active Enzyme Capture and Artificial Chaperone Activity

Area of Science:

• Biotechnology and Biomolecular Engineering
• Protein Engineering and Design
• Nanotechnology and Materials Science

Background:

• Protein cages are promising for encapsulating active cargoes like enzymes.
• Controlling the assembly and disassembly of protein cages under mild conditions remains a significant challenge.
• Achieving reversible cargo loading into protein cages is difficult.

Purpose of the Study:

• To develop a protein cage system capable of reversible cargo encapsulation under mild conditions.
• To demonstrate the formation of controllable three-dimensional arrays using these engineered protein cages.
• To investigate the impact of encapsulation on the enzyme's activity and stability.

Main Methods:

• Utilized an unusual ferritin cage protein engineered for triggerable assembly under mild conditions.
• Demonstrated reversible loading of protein cargoes, including an active enzyme.
• Investigated the formation of three-dimensional crystal lattices with the filled protein cages.

Main Results:

• Successfully achieved reversible filling of the engineered ferritin cages with active enzyme cargoes.
• Demonstrated the ability to arrange these filled cages into ordered three-dimensional crystal lattices.
• Observed a chaperone-like effect, enhancing both the thermostability and enzymatic activity of the encapsulated enzyme.

Conclusions:

• The engineered ferritin cage system provides a robust platform for reversible enzyme encapsulation and controlled spatial arrangement.
• This approach overcomes previous limitations in mild-condition protein cage assembly and cargo loading.
• The encapsulated enzymes benefit from increased stability and activity, highlighting the potential of this system for various applications.