Discipline: Chemistry and Chemical Sciences
Subcategory: Biochemistry (not Cell and Molecular Biology and Genetics)
Room: Exhibit Hall A
Anonda O'Brien - Lincoln University
Co-Author(s): Elizabeth B. Cerkez, Temple University, Philadelphia, PA and Daniel R. Strongin, Temple University, Philadelphia, PA
Ferritin proteins are ubiquitous in iron storage proteins in mammalian systems, but have also proven to be reactive photocatalysts and hosts for unique non-iron nanomaterials. The goal of this research was to harness manganese-ferritin for environmentally relevant reactions, in particular the catalysis of H2O2 decomposition. Manganese ferritin (MnFtn) was synthesized in buffer by the exposure, and subsequent oxidation, of manganese (II) chloride to apoferritin (empty protein). The resulting MnFtn was characterized by UV-Vis spectroscopy, transmission electron microscopy (TEM), and inductively coupled plasma-optical emission spectroscopy (ICP-OES). Post-reaction characterization revealed colloidal proteins containing manganese oxide cores. To study the decomposition of H2O2, the time resolved generation of O2 was completed with a luminescent dissolved oxygen probe. MnFtn was compared to apoferritin, birnessite (?-MnO2), and an amorphous manganese oxide (A-Mn) as a function of manganese loading. Apoferritin generated only slightly more dissolved O2 relative to controls without added catalyst, while MnFtn generated higher O2 concentrations. In general, reaction rate and total O2 generated increased with increasing Mn loading. Interestingly, O2 generation decreased as a function of ferritin loading. Finally, the O2 evolution curves of MnFtn were shaped differently compared to manganese oxide solids, indicating the reaction mechanisms may be different. The biomaterial-based system could potentially be used for on-demand O2 generation in biologically relevant environments, which could lead to numerous possibilities due to the importance of oxygen in the environment. Future work will aim to further quantify the rate of the reaction as a function of both manganese and protein loading. Additionally, the work will aim to be applied to remediation systems which would benefit from on demand O2 production.
Funder Acknowledgement(s): The NSF; Temple University
Faculty Advisor: Elizabeth Cerkez, Cerkeze1@temple.edu
Role: I synthesized MnFtn in buffer by the exposure, and subsequent oxidation, of manganese (II) chloride to apoferritin. After this I characterized MnFtn using UV-Vis spectroscopy, TEM, and ICP-OES. Post-reaction characterization revealed colloidal proteins containing manganese oxide cores. I then helped to study the decomposition of H2O2, using the time resolved generation of O2 was completed with a luminescent dissolved oxygen probe. After this I compared MnFtn to apoferritin, birnessite (?-MnO2), and an amorphous manganese oxide (A-Mn) as a function of manganese loading.