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A Dual-Metal-Catalyzed Sequential Cascade Reaction in an Engineered Protein Cage
Paul Ebensperger1, Mariia Zmyslia1, Philipp Lohner1
1Institute of Organic Chemistry, University of Freiburg, Alberstrasse 21, 79104, Freiburg i. Br., Germany.
Angewandte Chemie (International Ed. in English)
|February 17, 2023
Summary
Researchers created an artificial protein cage to house a dual-metal-tagged protein catalyst. This system efficiently catalyzes sequential reactions, producing valuable compounds like indoles and phenanthridines with high yields.
Area of Science:
- Biotechnology
- Catalysis
- Protein Engineering
Background:
- Protein cages offer a promising scaffold for organizing enzymatic reactions.
- Sequential cascade reactions require precise spatial and temporal control of catalysts.
- Metal catalysts are susceptible to deactivation in complex biological environments.
Purpose of the Study:
- To engineer an artificial protein cage for housing a dual-metal-tagged guest protein.
- To establish a two-step sequential cascade reaction within the protein cage.
- To evaluate the catalytic efficiency and stability of encapsulated metal catalysts.
Main Methods:
- Construction of a fusion protein (HaloTag-monomeric rhizavidin) for dual-metal tagging.
- Encapsulation of the tagged protein within an artificial protein cage.
- Sequential catalysis involving ruthenium- and gold-catalyzed reactions in aqueous solution.
Main Results:
- Successful creation of a protein cage housing a dual-metal-tagged guest protein.
- Catalysis of a two-step cascade reaction yielding indoles and phenanthridines with up to 66% overall yield.
- Demonstrated stabilization of metal catalysts against air, protein, and cell lysate deactivation.
Conclusions:
- Artificial protein cages can effectively compartmentalize and stabilize multi-catalytic systems.
- The engineered system enables efficient synthesis of complex molecules in aqueous media.
- Encapsulation provides a protective environment for metal catalysts, enhancing their operational stability.
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