Colloidal Protein–Silver Nanoparticle Metalloenzyme as Artificial Redox Biocatalyst
Efficient and sustainable catalytic processes are crucial for advancing green chemical manufacturing. Here, we describe the synthesis of novel silver artificial metalloenzymes in colloidal form in aqueous media and room temperature. The strategy is based on the in situ generation of silver nanoparti...
| Autores: | , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2025 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/379479 |
| Acceso en línea: | http://hdl.handle.net/10261/379479 |
| Access Level: | acceso abierto |
| Palabra clave: | Silver Metalloenzymes Redox enzymes Colloidal Nanoparticles |
| Sumario: | Efficient and sustainable catalytic processes are crucial for advancing green chemical manufacturing. Here, we describe the synthesis of novel silver artificial metalloenzymes in colloidal form in aqueous media and room temperature. The strategy is based on the in situ generation of silver nanoparticles by a genetically modified Geobacillus thermocatenulatus lipase (GTL) in the active site as an inducer and scaffold protein, producing an enzyme–Ag bioconjugate. Using a structural analysis of the formation of silver nanoparticles by XRD and UV spectra, we found the formation of Ag2O species with nanoparticles of around 11 nm average diameter size. Gel filtration chromatography demonstrated the presence of single protein molecules in the bioconjugates, although silver nanoparticles were initially formed by cysteine coordination in the active site but later were formed in other parts of the protein (five AgNPs per molecules, which is in concordance with the UV size). The enzyme structure was altered after nanoparticle formation and Ag-S interaction, which was observed in fluorescence analysis. This new enzyme showed reductive activity against p-nitrophenol to p-amino and a high conversion > 99% in the reduction of acetophenone to phenylethanol, although the enantioselective was quite moderate but higher in water that in the presence of co-solvents. Finally, oxidase-like activity was evaluated in the direct oxidation of phenylethanol to acetophenone in water, obtained at around a 23% yield of ketone after 60 h. |
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