Influence of Cupric (Cu 2+ ) Ions on the Iron Oxidation Mechanism by DNA-Binding Protein from Starved Cells (Dps) from Marinobacter nauticus .
João P L GuerraDaniela PenasPedro TavaresAlice S PereiraPublished in: International journal of molecular sciences (2023)
Dps proteins (DNA-binding proteins from starved cells) are multifunctional stress defense proteins from the Ferritin family expressed in Prokarya during starvation and/or acute oxidative stress. Besides shielding bacterial DNA through binding and condensation, Dps proteins protect the cell from reactive oxygen species by oxidizing and storing ferrous ions within their cavity, using either hydrogen peroxide or molecular oxygen as the co-substrate, thus reducing the toxic effects of Fenton reactions. Interestingly, the interaction between Dps and transition metals (other than iron) is a known but relatively uncharacterized phenomenon. The impact of non-iron metals on the structure and function of Dps proteins is a current topic of research. This work focuses on the interaction between the Dps from Marinobacter nauticus (a marine facultative anaerobe bacterium capable of degrading petroleum hydrocarbons) and the cupric ion (Cu 2+ ), one of the transition metals of greater biological relevance. Results obtained using electron paramagnetic resonance (EPR), Mössbauer and UV/Visible spectroscopies revealed that Cu 2+ ions bind to specific binding sites in Dps, exerting a rate-enhancing effect on the ferroxidation reaction in the presence of molecular oxygen and directly oxidizing ferrous ions when no other co-substrate is present, in a yet uncharacterized redox reaction. This prompts additional research on the catalytic properties of Dps proteins.
Keyphrases
- hydrogen peroxide
- aqueous solution
- induced apoptosis
- oxidative stress
- single molecule
- binding protein
- circulating tumor
- quantum dots
- reactive oxygen species
- nitric oxide
- cell free
- cell cycle arrest
- single cell
- human health
- endoplasmic reticulum stress
- wastewater treatment
- iron deficiency
- signaling pathway
- electron transfer
- health risk
- liver failure
- cell death
- water soluble
- health risk assessment
- stem cells
- transcription factor
- intensive care unit
- metal organic framework
- nucleic acid
- amino acid
- hepatitis b virus
- respiratory failure
- drinking water
- circulating tumor cells
- dna binding