Radical pairs in excited donor-bridge-acceptor (D-B-A) systems under magnetic fields offer promising new platforms for biological imaging and quantum computing. Examining the fluorescence intensity output of these D-B-A systems at varying magnetic fields provides deeper insight into the magnetic field-dependent singlet-triplet interconversion rates that enable these applications. Our work utilizes kinetic master equation modelling, through which we aim to provide a better understanding of relative populations of excited states during fluorescence decay and establish parameters for the singlet-triplet interconversion rates, at different magnetic field strengths. This will form the foundation for a more rigorous quantum mechanical treatment. Future work will look to refine the model and use it to compare the magnetic field sensitivity of different D-B-A frameworks in order to optimize interconversion rates for specific experimental applications. This will inform the design of new D-B-A systems with optimized magnetic field sensing properties.

The actin-regulating protein, cofilin, is proposed to affect actin mesh disassembly within oocytes and thus directly impact the fertility of Drosophila. RNAi knockdown of cofilin has been shown to prevent actin mesh disassembly. In an effort to study this mechanism further, flare and coronin, which have been associated with actin breakdown, were knocked-down via RNAi. We hypothesized that reducing levels of flare and/or coronin would lead to cofilin dysfunction and delayed mesh disassembly within the oocyte. The actin mesh was only present in Stage 9 and 10a oocytes and not present in Stage 10b or 11 oocytes of the control/wildtype flies; however, RNAi knockdown of flare and coronin revealed a potential delay in breakdown of this actin mesh. Analysis of data from these experiments show lower overall mesh intensities in the RNAi knockdowns of both flare and coronin, indicating a possible contribution to actin mesh disassembly. This brings us closer to understanding the mechanisms driving infertility in Drosophila and in humans alike.

Qubits are units of information that exist as superpositions of 0 and 1, and are the foundational basis for quantum information systems to perform calculations exponentially faster than that of their classical counterparts. Despite extensive development, many candidates face intrinsic limitations including decoherence and extreme energetic requirements. Biological qubits possess key characteristics to address such challenges yet remain as untapped, promising alternatives. Here, we focus on vanadyl, as the large energy gap between its ground and excited state orbitals results in the quenching of its ground state orbital angular momentum, thereby decoupling its electron spin from environmental lattice vibrations and enhancing coherence. To further leverage and bolster these properties, we turned to Desulfovibrio desulfuricans rubredoxin, a small and robust protein with previously known promiscuity in metal coordination. Here, we engineered five novel constructs to introduce oxygen-donating ligands favorable for vanadyl binding and established initial experimental frameworks to screen and optimize expression, purification, and reconstitution workflows to enable downstream spectroscopic characterization. Our findings reveal distinct hyperfine electron paramagnetic resonance splitting and ultraviolet-visible optical characteristics that indicate successful vanadyl incorporation, establishing a promising foundation for adapting proteins for functions beyond nature in the context of emerging quantum technologies.

Several human pathogens bind the apical domain of transferrin receptor 1 (TfR1) to invade cells, which indicates TfR1 as a target for neutralization of those pathogens. To develop broadly acting therapeutics against those pathogens, we aim to prepare an effective blockade of their binding interactions. I therefore analyzed binding sites on the TfR1 apical domain to evaluate interfacing residues and set out to humanize existing antibodies that bind this domain. I also assessed the conservation of apical domain residues and compared binding of antibody OKT9 to apical domains derived from different mammals via enzyme-linked immunosorbent assay (ELISA). I found that OKT9 selectively bound the human apical domain. Residues R208 and Y247 were unique to human TfR1 and likely essential for binding. By outlining binding residues in OKT9-TfR1 models, AlphaFold 3 indicated R208, but not Y247, as essential for binding. An ELISA comparing selectively mutated apical domains confirmed R208 as necessary for binding. However, dissimilar apical domains, modified to present R208 and adjacent residues, lacked significant binding via ELISA. The linear epitope containing R208 is insufficient for binding of OKT9. For therapeutic purposes, OKT9 must be humanized to decrease its immunogenicity. Accordingly, I used AlphaFold 3 to verify the binding capabilities of humanized OKT9 variants. Ongoing analyses of the TfR1 binding interface are expected to facilitate the design of improved binders that deny the binding of pathogens to human TfR1.