Cytochrome C with peroxidase-like activity encapsulated inside the small DPS protein nanocage
| Autor: | Hitesh Kumar Waghwani, Trevor Douglas |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Hemeprotein
DNA-binding protein from starved cells Protein subunit ved/biology.organism_classification_rank.species Biomedical Engineering Capsules 010402 general chemistry 01 natural sciences Antioxidants 03 medical and health sciences chemistry.chemical_compound General Materials Science Polyhistidine-tag 030304 developmental biology chemistry.chemical_classification 0303 health sciences biology ved/biology Cytochrome c Sulfolobus solfataricus Cytochromes c General Chemistry General Medicine 0104 chemical sciences DNA-Binding Proteins Kinetics Enzyme chemistry biology.protein Biophysics Peroxidase |
| Zdroj: | Journal of materials chemistry. B. 9(14) |
| ISSN: | 2050-7518 |
| Popis: | Nature utilizes self-assembled protein-based structures as subcellular compartments in prokaryotes to sequester catalysts for specialized biochemical reactions. These protein cage structures provide unique isolated environments for the encapsulated enzymes. Understanding these systems is useful in the bioinspired design of synthetic catalytic organelle-like nanomaterials. The DNA binding protein from starved cells (Dps), isolated from Sulfolobus solfataricus, is a 9 nm dodecameric protein cage making it the smallest known naturally occurring protein cage. It is naturally over-expressed in response to oxidative stress. The small size, natural biodistribution to the kidney, and ability to cross the glomerular filtration barrier in in vivo experiments highlight its potential as a synthetic antioxidant. Cytochrome C (CytC) is a small heme protein with peroxidase-like activity involved in the electron transport chain and also plays a critical role in cellular apoptosis. Here we report the encapsulation of CytC inside the 5 nm interior cavity of Dps and demonstrate the catalytic activity of the resultant Dps nanocage with enhanced antioxidant behavior. The small cavity can accommodate a single CytC and this was achieved through self-assembly of chimeric cages comprising Dps subunits and a Dps subunit to which the CytC was fused. For selective isolation of CytC containing Dps cages, we utilized engineered polyhistidine tag present only on the enzyme fused Dps subunits (6His-Dps-CytC). The catalytic activity of encapsulated CytC was studied using guaiacol and 3,3′,5,5′-tetramethylbenzidine (TMB) as two different peroxidase substrates and compared to the free (unencapsulated) CytC activity. The encapsulated CytC showed better pH dependent catalytic activity compared to free enzyme and provides a proof-of-concept model to engineer these small protein cages for their potential as catalytic nanoreactors. |
| Databáze: | OpenAIRE |
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