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Protein Film Infrared Electrochemistry Demonstrated for Study of H2 Oxidation by a [NiFe] Hydrogenase
Published on: December 4, 2017
Adenine oxidation by pyrite-generated hydroxyl radicals
Corey A Cohn1, Shawn C Fisher, Bruce J Brownawell
1Center for Environmental Molecular Science, Department of Geosciences, Stony Brook University, Stony Brook, N,Y, 11794-2100 USA. martin.schoonen@stonybrook.edu.
Geochemical Transactions
|April 28, 2010
Summary
Particulate matter exposure can cause oxidative stress. Pyrite particles generate reactive oxygen species (ROS) that oxidize adenine, forming 8-oxoadenine and 2-hydroxyadenine, similar to Fenton reactions.
Area of Science:
- Environmental toxicology
- Biochemistry
- Materials science
Background:
- Particulate matter exposure is linked to adverse health effects due to reactive oxygen species (ROS) and biomolecule oxidation.
- Understanding particle-induced oxidative stress requires evaluating ROS formation and subsequent oxidation products.
- Pyrite particles generate hydroxyl radicals and degrade nucleic acids, but their reactions with nucleic acid bases are not fully understood.
Purpose of the Study:
- To compare adenine oxidation by Fenton-generated hydroxyl radicals versus pyrite-generated hydroxyl radicals.
- To identify the oxidation products of adenine in reactions initiated by pyrite particles.
- To elucidate the role of hydrogen peroxide and hydroxyl radicals in pyrite-induced adenine oxidation.
Main Methods:
- Comparing adenine oxidation using Fenton chemistry (Fe2+/H2O2) and pyrite suspensions.
- Investigating the effect of pyrite loading on adenine oxidation rate.
- Assessing the impact of catalase and ethanol on adenine oxidation in pyrite suspensions.
- Identifying adenine oxidation products using analytical techniques.
Main Results:
- Adenine oxidation occurred in pyrite suspensions without added hydrogen peroxide.
- The rate of adenine oxidation by pyrite was dependent on pyrite loading.
- Catalase and ethanol inhibited adenine oxidation, confirming the involvement of hydrogen peroxide and hydroxyl radicals.
- Pyrite-initiated hydroxyl radicals produced the same oxidation products (8-oxoadenine, 2-hydroxyadenine) as Fenton-generated hydroxyl radicals.
Conclusions:
- Pyrite particles can generate reactive oxygen species that oxidize adenine, a nucleic acid base.
- The mechanism of adenine oxidation by pyrite-generated hydroxyl radicals is similar to that of Fenton chemistry.
- While direct particle-cell contact may be limited, ROS formation near cells can contribute to oxidative stress.
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