Glutamine is the most abundant amino acid in serum and is heavily implicated in several cellular signaling pathways for protein synthesis, energy production, and overall carbon and nitrogen metabolism. Glutamine metabolism is especially of interest in cancer cells, as it has been observed that several cancers fail to proliferate under glutamine starvation. To study glutamine dynamics, we created the intracellular glutamine optical reporter (iGlo) biosensor for fluorescent microscopy experiments; it has a glutamine-sensing domain and a green fluorescent protein (GFP) that lights up when bound to glutamine. This project centers around the hypothesis that inhibiting glutamine breakdown will upregulate glycolysis. To view the metabolic flux through these pathways, HeLa cells were co-transfected with iGlo and a red-fluorescent biosensor for lactate called R-iLACCO; these cells were treated with CB-839, an inhibitor of the enzyme glutaminase, which breaks glutamine into glutamate and ammonia to feed glutamate into the Krebs cycle. In multiplexed fluorescent imaging of these biosensors, both the glutamine and lactate responses can be quantified by the fluorescent intensity of the cells over time. After analysis, both an accumulation of glutamine and an increase in lactate production are observed. Thus, there may be crosstalk within the cell that connects glutamine metabolism to glycolysis, as cells are able to adjust the flux between these pathways to meet their energetic demands.

Natural products are a rich source of structurally diverse small molecules produced by bacteria, plants, and fungi. A major driver of this diversity is tailoring enzymes that install complex functional groups through specialized chemistry. Among these, nonheme diiron oxygenases (HDOs) are an emerging class of enzymes capable of diverse oxidative transformations, though many remain poorly characterized. Here, we investigate a three-enzyme biosynthetic gene cluster from Carbellonia insecticola. Bioinformatic analysis suggests CabA is a PLP-didomain enzyme, CabB is an ATP-grasp ligase, and CabC is a putative HDO with limited similarity to characterized homologs. To contextualize CabC within the HDO family, we constructed a sequence similarity network (SSN) of known HDOs from the literature. CabC segregates into a distinct cluster, indicating substantial sequence divergence and suggesting a potentially unique function. Despite this divergence, CabC retains the conserved HXX(D/E)XXH motif characteristic of diiron coordination, supporting its classification as an HDO. The presence of this motif alongside divergent sequence features suggests preservation of canonical diiron-binding chemistry with possible novel reactivity. Together, these findings support a conserved biosynthetic gene cluster model in which CabC performs a novel oxidation step in noncanonical dipeptide biosynthesis, expanding the functional diversity of HDO chemical logic and enzymatic machinery.

Sulfur is a promising alternative to conventional cathode materials in lithium-ion batteries due to its much larger theoretical capacity. However, in practice, polysulfide-shuttling has limited the efficacy of these batteries. In order to circumvent this issue, we explore a rapid graphene-wrapping method that has shown promising results in limiting detrimental effects of polysulfide shuttling. My research tests the influence of varying sulfur particle sizes on graphene-wrapping effectiveness and battery performance. The sizes tested include bulk sulfur, mortar and pestled, ball milled, and “nano” sulfur. After confirming sulfur particle size via Scanning Electron Microscopy (SEM) and Particle Size Determination (PSD), sulfur-graphene oxide cathode coin cell battery performance was assessed using cyclical charging and discharging. Results show that sulfur size does not significantly impact battery specific capacity performance given long-term cycle testing. These findings suggest an efficient mechanism to address the rising energy needs of a rapidly evolving technological space.

The oral cavity is home to a diverse microbial ecosystem containing over 600 bacterial species that interact with each other and the human host through secondary metabolites. These natural products are encoded by biosynthetic gene clusters (BGCs), and are essential for maintaining oral health. Despite some successful characterizations of oral bioactive natural products, most studies focus on metabolites produced by oral pathogens, neglecting the biosynthetic potential of health-associated microbes and their metabolites’ role in maintaining microbial homeostasis. To address this gap, this project aims to uncover new natural products from health-associated oral bacteria that may have a role in promoting oral health. We hypothesize that these metabolites play a causal role in promoting microbial homeostasis. To test this, we integrate genome-mining approaches with a systematic bioinformatic pipeline. Specifically, BGCs from health-associated bacterial genomes are detected and annotated using antiSMASH. BGCs are then profiled against publicly available metagenomic and metatranscriptomic datasets using BiG-MAP to evaluate their relative abundance and transcription across healthy and diseased samples. Candidate BGCs are chosen based on their predicted novelty, enrichment in healthy samples, and metatranscriptomic upregulation in health-associated microbiomes. Future work will focus on metabolite isolation and structural characterization, followed by functional assays to evaluate biological activity of these BGCs.

This abstract has been withheld from publication.