A breakthrough in artificial photosynthesis – researchers produce hybrid solid catalysts
Researchers used intracellular engineering to produce hybrid solid catalysts for artificial photosynthesis using protein crystals. These catalysts, created through genetically modified bacteria, are highly active, durable, and environmentally friendly, paving the way for a new approach in enzyme immobilization.
Researchers at Tokyo Tech have demonstrated that intracellular engineering is an effective way to create functional protein crystals with promising catalytic properties. By harnessing genetically modified bacteria as a green synthesis platform, researchers have produced hybrid solid catalysts for synthetic… Photosynthesis. These catalysts show high activity, stability, and durability, highlighting the potential of the proposed innovative approach.
Protein crystals, like ordinary crystals, are well-organized molecular structures that have diverse properties and enormous potential for customization. They can be synthesized naturally from materials found inside cells, which not only significantly reduces synthesis costs but also reduces their environmental impact.
Although protein crystals are promising catalysts because they can host various functional molecules, current techniques only allow the attachment of small molecules and simple proteins. Thus, it is necessary to find ways to produce protein crystals bearing both natural enzymes and synthetic functional molecules to utilize their full potential for enzyme immobilization.
Against this background, a team of researchers from the Tokyo Institute of Technology (Tokyo Tech) led by Professor Takafumi Ueno has developed an innovative strategy for producing hybrid solid-state catalysts based on protein crystals. As described in their paper published in Nano messages Jul 12, 2023 Their approach combines in-cell and simple engineering in the laboratory Process for producing catalysts for artificial photosynthesis.
Illustration of the research. Image source: Professor Takafumi Ueno, Tokyo Institute of Technology
The building block of the hybrid catalyst is a protein monomer derived from A virus Which is afflicted Bombyx mori silkworm. The researchers inserted the gene that codes for this protein Escherichia coli Bacteria, where the produced monomers formed trimers, which, in turn, spontaneously assemble into stable polyhedral crystals (PhCs) by binding to each other through the N-terminal alpha helix (H1). In addition, the researchers introduced a modified version of the formate dehydrogenase (FDH) gene from A Classify Yeast in coli bacteria Genome. This gene caused bacteria to produce FDH enzymes with H1 termini, leading to the formation of H1-FDH@PhC hybrid crystals inside cells.
The team extracted the hybrid crystals from coli bacteria Bacteria through sonication, gradient centrifugation, and soaking in a solution containing a synthetic photosensitizer called eosin Y (EY). As a result, the protein monomers, which were genetically modified such that their central channel could host the eosin Y molecule, facilitated stable binding of EY to the hybrid crystal in bulk.
Through this ingenious process, the team was able to produce highly active, recyclable and thermally stable EY·H1-FDH@PhC catalysts that can convert carbon dioxide (CO).2) to format (HCOO–) when exposed to light, simulating the process of photosynthesis. In addition, they maintained 94.4% of their catalytic activity after immobilization compared to that of the free enzyme. “The conversion efficiency of the proposed hybrid crystal was much higher than previously reported compounds for enzymatic artificial photosynthesis based on FDH,” Professor Ueno highlights. “Moreover, the hybrid PHC remained in the solid protein aggregation state after bearing both Alive And in the laboratory engineering processes, demonstrating the remarkable crystallization ability and strong plasticity of PCCs as encapsulated scaffolds.
Overall, this study showcases the potential of bioengineering in facilitating the synthesis of complex functional materials. “A combination of Alive And in the laboratory Protein crystal encapsulation technologies are likely to provide an efficient and environmentally friendly strategy for research in the fields of nanomaterials and artificial photosynthesis,” concludes Professor Ueno.
We certainly hope that these efforts will lead us to a greener future!
Reference: “Engineering Intracellular Protein Crystals into Hybrid Solid Catalysts for Artificial Photosynthesis” by Tezeng Pan, Basudev Mighty, Satoshi Abe, Taiki Morita, and Takafumi Ueno, 12 July 2023, Nano messages.
doi: 10.1021/acs.nanolett.3c02355
