Biochemistry Commons^™

Characterizing Substituted Imidazolidinetriones As A Novel Class Of Pyruvate Carboxylase Inhibitors, Nicholas O. Schneider

Dissertations (1934 -)

Pyruvate carboxylase (PC) is implicated in a variety of diseases, including type-2 diabetes, cancer, and bacterial/viral infections. However, there are currently no molecular tools capable of precisely manipulating PC activity both in vitro and in vivo. This dissertation describes the identification and characterization of 1,3-disubstituted imidazolidinetriones as a novel class of potent, selective, and permeable allosteric inhibitors of Staphylococcus aureus PC. Based on kinetic, structural, and biophysical data, this class of inhibitors is hypothesized to bind at the noncatalytic “exo binding” site on PC. This exo binding site is reportedly important for catalysis, but it had not previously been considered …

The Anaerobic Rose Chamber (Arc): Novel Applications For Probing Clostridioides Difficile Dynamics, Tatiana Zvonareva

Chemistry & Biochemistry Theses & Dissertations

Clostridioides difficile infection (CDI) is an urgent public health threat with a high rate of recurrence and limited treatment options. Caused by the anaerobic intestinal pathogen C. difficile, this disease affects up to 500,000 Americans annually. Despite progress in our understanding of CDI pathophysiology, the lack of effective and accessible experimental platforms compatible with obligate anaerobe physiology hinders the advancement of treatment therapy. The application of in vivo models has been indispensable in understanding CDI pathophysiology, probing the complexity of the host response to the microbe, and establishing treatment protocols, and it continues to be essential in preclinical testing. …

Synthesis Of Drug-Like Molecules And Investigation Of Their Biological Activity, Duyen Nguyen '25, Sunny Nguyen '26, Jeffery A. Hansen

Annual Student Research Poster Session

This study examines the products derived from the ring-opening reactions of two novel epoxides—chlorobenzene epoxide and furan epoxide—highlighting their notable biological activity, particularly in the context of potential anticancer agents. One key finding: a synthesized stereoisomer of a hexylamine-derived β-amino alcohol exhibited a remarkably low LC50 value of 6.6 ppm in the Brine Shrimp Lethality Assay, significantly outperforming the other isomer compound’s LC50 value, at 13 ppm. This discovery underscores the critical role of stereochemistry in enhancing bioactivity, as evidenced by the distinct physical and chemical properties of the two hexylamine-derived isomers, including differences in appearance and solubility. Building on …

E-Textbook For Better Learning In Chemistry 120, Anh Vu '27, Jeffery A. Hansen

Annual Student Research Poster Session

Organic chemistry is a highly visual subject since organic compounds are 3D objects. For this reason, in order to fully understand the composition, properties, and chemistry of these compounds, it is essential to understand and visualize their 3D structures. Nevertheless, there is a frequent necessity to depict organic substances on 2D surfaces, such as paper, a computer screen, or a whiteboard. As a result, one of the biggest obstacles we will face is learning these molecules in a 2D format while maintaining an accurate understanding of 3D nature. The purpose of this e-textbook is to fully utilize the digital medium …

Designing An Attachment Assay For Epidermal Cell-To-Cell Attachment, Tiala Ortega '26, Colleen L. Doçi

Annual Student Research Poster Session

Cell adhesion includes various processes and is essential in cell communication and regulation. The mechanical interactions between a cell and its extracellular matrix control the behavior and function of a cell. In this project, we are studying cell attachment in different ways. The epidermal monostrato layer is a vertical and horizontal interaction and is not accounted for in usual assay protocols so I wanted to investigate this by creating an assay including multiple cell layers, a monolayer and an attached layer, to further develop a protocol for optimal cell-to-cell attachment. I hypothesized that the number of cell attachments to the …

Comparison Of Two Disaccharides And Their Saccharide Components In Aot Reverse Micelles: Impacts Of D-Trehalose And D-Sucrose, Delaney Collier '25, Bridget L. Gourley, Nancy E. Levinger

Annual Student Research Poster Session

Reverse micelles, featuring an AOT surfactant with a polar head group and nonpolar tail, encapsulate a polar phase at the nanoscale. With water as the polar phase, the nanoconfined water pool interactions and water-interface interactions mimic biological nanoconfinement. Thus, we investigated the impact of osmolytes on AOT reverse micelles to explore the role they play in biological systems. We investigated two disaccharides, D-trehalose and D-sucrose, and their monosaccharide components, glucose+glucose and glucose+fructose. We chose these molecules for their biological significance and to allow us to investigate whether subtle structural changes in the osmolyte impacts the intermolecular interactions in confinement as …

A Comparative Analysis Of Urea Vs. Acetamide In Aot Reverse Micelles, Kate Walsh '26, Bridget Gourley, Nancy E. Levinger

Annual Student Research Poster Session

In our exploration of the interactions between water and amide osmolytes, we focused on the effects of urea and acetamide on the stability of reverse micelles (RMs) formed with Sodium Bis(2-ethylhexyl)sulfosuccinate (AOT) in isooctane. Water, with its unique polarity and its ability to facilitate hydrogen and proton transfer, played a crucial role in our study, as we aimed to uncover how these amides would influence micellar behaviour. Our results revealed a compelling contrast between urea and acetamide. Acetamide, with its lower polarity due to a methyl group substitution, demonstrated superior solubility and significantly reduced precipitate formation compared to urea. This …

Enzyme Encapsulation Within The Hk97 Virus-Like Particle: An Investigation Of Substrate Inhibition Kinetics Within A Confined And Crowded Environment, Joseph B. Lively

Chemistry Theses

Substrate inhibition is a paradoxical phenomenon observed in enzyme kinetics where increasing substrate concentrations lead to a marked decrease in the rates of enzyme-catalyzed reactions. Affecting an estimated 20% of studied enzymes, substrate inhibition poses significant challenges to the understanding of their function in essential biological processes and to their exploitation in industrial and therapeutic contexts. Studies show substrate inhibition to be a real limitation in vitro and rational conclusions have been drawn to explain the relevance of substrate inhibition in the self-regulation of biological pathways. However, there is currently no consensus on what role substrate inhibition plays in vivo …

Considerations For Widespread Implementation Of Blood-Based Biomarkers Of Alzheimer's Disease, Michelle Mielke, Matthew Anderson, Wesson Ashford, Andreas Jeromin, Pei-Jung Lin, Allyson Rosen, Jamie Tyrone, Lawren Vandevrede, Deanna Willis, Zul Merali

Brain and Mind Institute

Diagnosing Alzheimer's disease (AD) poses significant challenges to health care, often resulting in delayed or inadequate patient care. The clinical integration of blood-based biomarkers (BBMs) for AD holds promise in enabling early detection of pathology and timely intervention. However, several critical considerations, such as the lack of consistent guidelines for assessing cognition, limited understanding of BBM test characteristics, insufficient evidence on BBM performance across diverse populations, and the ethical management of test results, must be addressed for widespread clinical implementation of BBMs in the United States. The Global CEO Initiative on Alzheimer's Disease BBM Workgroup convened to address these challenges …

Investigating Neurite Outgrowth Influenced By Breast Cancer Progression Using In Vitro Models Of Collagen I Hydrogels, Emma Waskom '27, Nikolas Ala-Kokko, Younghye Song

Annual Student Research Poster Session

Through the use of vitro modeling of tumor progression, using collagen I hydrogels and progressing cell lines, a demonstration of the interactions between breast cancer cells and nerve cells can be investigated. With these models, our goal is to compare the measurement of outgrowth of nerve cells through the use of supplemented NGF and co cultures of breast cancer cells. Human MCF-CA1a.cl1, -AneoT, and -10A, adipose-derived stem cells (ASCs), and rat PC-12 cells, were all passaged from 2D cultures and cultured in a collagen I hydrogen at a cell density of 250,000 cells/ml of media. Collagen hydrogels were then made …

Knockdown Of Ketohexokinase Versus Inhibition Of Its Kinase Activity Exert Divergent Effects On Fructose Metabolism, Se-Hyung Park, Taghreed Fadhul, Lindsey R. Conroy, Harrison A. Clarke, Ramon Sun, Kristina Wallenius, Jeremie Boucher, Gavin O'Mahony, Alessandro Boianelli, Marie Persson, Sunhee Jung, Cholsoon Jang, Analia S. Loria, Genesee J. Martinez, Zachary A. Kipp, Evelyn A. Bates, Terry D. Hinds Jr., Senad Divanovic, Samir Softic

Markey Cancer Center Faculty Publications

Excessive fructose intake is a risk factor for the development of obesity and its complications. Targeting ketohexokinase (KHK), the first enzyme of fructose metabolism, has been investigated for the management of metabolic dysfunction–associated steatotic liver disease (MASLD). We compared the effects of systemic, small molecule inhibitor of KHK enzymatic activity with hepatocyte-specific, N-acetylgalactosamine siRNA–mediated knockdown of KHK in mice on an HFD. We measured KHK enzymatic activity, extensively quantified glycogen accumulation, performed RNA-Seq analysis, and enumerated hepatic metabolites using mass spectrometry. Both KHK siRNA and KHK inhibitor led to an improvement in liver steatosis; however, via substantially different mechanisms, KHK …

Predicting The Pathway Involvement Of All Pathway And Associated Compound Entries Defined In The Kyoto Encyclopedia Of Genes And Genomes, Erik D. Huckvale, Hunter Moseley

Markey Cancer Center Faculty Publications

Background/Objectives: Predicting the biochemical pathway involvement of a compound could facilitate the interpretation of biological and biomedical research. Prior prediction approaches have largely focused on metabolism, training machine learning models to solely predict based on metabolic pathways. However, there are many other types of pathways in cells and organisms that are of interest to biologists. Methods: While several publications have made use of the metabolites and metabolic pathways available in the Kyoto Encyclopedia of Genes and Genomes (KEGG), we downloaded all the compound entries with pathway annotations available in the KEGG. From these data, we constructed a dataset where each …

Upregulation Of Fatty Acid Synthase Increases Activity Of Β-Catenin And Expression Of Notum To Enhance Stem-Like Properties Of Colorectal Cancer Cells, Courtney O. Kelson, Josiane Weber Tessmann, Mariah E. Geisen, Daheng He, Chi Wang, Tianyan Gao, B. Mark Evers, Yekaterina Y. Zaytseva

Markey Cancer Center Faculty Publications

Dysregulated fatty acid metabolism is an attractive therapeutic target for colorectal cancer (CRC). We previously reported that fatty acid synthase (FASN), a key enzyme of de novo synthesis, promotes the initiation and progression of CRC. However, the mechanisms of how upregulation of FASN promotes the initiation and progression of CRC are not completely understood. Here, using Apc/VillinCre and ApcMin mouse models, we show that upregulation of FASN is associated with an increase in activity of β-catenin and expression of multiple stem cell markers, including Notum. Genetic and pharmacological downregulation of FASN in mouse adenoma organoids decreases the activation of β-catenin …

Effect Of Heat Stress On The Expression Of Circulating Cyto(Chemo)Kine And Inflammatory Markers In Broiler Chickens Selected For High- Or Low-Water Efficiency, Elizabeth S. Greene, Travis Tabler, Walter G. Bottje, Sara Orlowski, Sami Dridi

Poultry Science Faculty Publications and Presentations

Background:

Water scarcity is a current, significant global concern that will only increase under the pressure of climate change. Improving water efficiency of poultry is a new and promising area to help temper agriculture's future impact on fresh water availability. Here, we explored the effects of acute heat stress (HS) on circulating stress and inflammatory markers in 2 lines of broilers divergently selected for water efficiency. Methods:

Male chicks from low (LWE) and high water efficient (HWE) lines were raised in 12 environmental chambers (2 pens/chamber, 6 chambers/line, 20 birds/pen) under normal conditions until day 28. On day 29, birds …

Characterization Of Stealth Liposome-Based Nanoparticles Encapsulating Acat1/Soat1 Inhibitor F26: Potential Therapeutics For Niemann-Pick Type C And Other Neurodegenerative Diseases., Junghoon Lee

Dartmouth College Ph.D Dissertations

Cholesterol dysregulation is implicated in neurodegenerative diseases such as Alzheimer's disease (AD), Parkinson’s disease (PD), Huntington’s disease (HD) and Niemann-Pick type C disease (NPCD). This study focused on evaluating the potent ACAT1 inhibitor, F26, as a therapeutic strategy for NPCD. F26 demonstrated superior ACAT1 inhibition and efficacy compared to the previously studied inhibitor, F12511, both in vitro and in vivo. Notably, F26 exhibited enhanced pharmacokinetic properties, including prolonged duration of action and better brain retention, making it a more promising candidate for treating neurodegenerative diseases.

F26 was encapsulated in a liposome-based nanoparticle system, DSPE-PEG2000 with phosphatidylcholine (PC), for enhancing its …

Crystal Archer: Profile Of The Newest Chbc Faculty Member, Danna Jaimes-Fajardo, Jeremy J. Smith, Lutishoor Salisbury

University Libraries Faculty Publications and Presentations

Presents the research profile of Crystal Archer, Assistant Professor, Chemistry and Biochemistry department. It highlights her research interests, education, and impact of her research.

Proteomic Analysis Reveals Major Proteins And Pathways That Mediate The Effect Of 17-Β-Estradiol In Cell Division And Apoptosis In Breast Cancer Mcf7 Cells, Zhenqi Zhou, Brihget Sicairos, Jianhong Zhou, Yuchun Du

Biological Sciences Faculty Publications and Presentations

Despite extensive research, the genes/proteins and pathways responsible for the physiological effects of estrogen remain elusive. In this study, we determined the effect of estrogen on global protein expression in breast cancer MCF7 cells using a proteomic method. The expression of 77 cytosolic, 74 nuclear, and 81 membrane/organelle proteins was significantly altered by 17-β-estradiol (E2). Protein enrichment analyses suggest that E2 may stimulate cell division primarily by promoting the G1 to S phase transition and advancing the G2/M checkpoint. The effect of E2 on cell survival was complex, as it could simultaneously enhance and inhibit apoptosis. Bioinformatics analysis suggests that …

Accurate Crystal Structure Prediction Of New 2d Hybrid Organic–Inorganic Perovskites, Nima Karimitari, William J. Baldwin, Evan W. Muller, Zachary J.L. Bare, W. Joshua Kennedy, Gábor Csányi, Christopher Sutton

Faculty Publications

Low-dimensional hybrid organic–inorganic perovskites (HOIPs) are promising electronically active materials for light absorption and emission. The design space of HOIPs is extremely large, as a variety of organic cations can be combined with different inorganic frameworks. This not only allows for tunable electronic and mechanical properties but also necessitates the development of new tools for in silico high throughput analysis of candidate materials. In this work, we present an accurate, efficient, and widely applicable machine learning interatomic potential (MLIP) trained on 86 diverse experimentally reported HOIP materials. This MLIP was tested on 73 experimentally reported perovskite compositions and achieves a …

Nanopore Signal Deviations From Pseudouridine Modifications In Rna Are Sequence-Specific: Quantification Requires Dedicated Synthetic Controls, Amr Makhamreh, Sepideh Tavakoli, Ali Fallahi, Xinqi Kang, Howard Gamper, Mohammad Nabizadehmashhadtoroghi, Miten Jain, Ya-Ming Hou, Sara H Rouhanifard, Meni Wanunu

Department of Biochemistry and Molecular Biology Faculty Papers

Chemical modifications to mRNA respond dynamically to environmental cues and are important modulators of gene expression. Nanopore direct RNA sequencing has been applied for assessing the presence of pseudouridine (ψ) modifications through basecalling errors and signal analysis. These approaches strongly depend on the sequence context around the modification, and the occupancies derived from these measurements are not quantitative. In this work, we combine direct RNA sequencing of synthetic RNAs bearing site-specific modifications and supervised machine learning models (ModQuant) to achieve near-analytical, site-specific ψ quantification. Our models demonstrate that the ionic current signal features important for accurate ψ classification are sequence …

Inorganic Pyrophosphate Plasma Levels In Patients With Ggcx-Associated Pxe-Like Phenotypes, Qiaoli Li, Catherine Troutman, Mary Peckiconis, Tamara Wurst, Sharon Terry

Department of Biochemistry and Molecular Biology Faculty Papers

ntroduction: Pseudoxanthoma elasticum (PXE) is an autosomal recessive ectopic calcification disorder clinically affecting the skin, eyes, and vascular system. Most cases of PXE are caused by inactivating pathogenic variants in the ABCC6 gene encoding a hepatic transmembrane efflux transporter, which facilitates the extracellular release of ATP, the precursor of inorganic pyrophosphate (PPi), a potent endogenous inhibitor of calcification. Pathogenic variants in GGCX, encoding γ-glutamyl carboxylase required for activation of vitamin K-dependent coagulation factors as well as matrix Gla protein (MGP) and Gla-rich protein (GRP), two inhibitors of ectopic calcification, have also been reported to cause cutaneous changes like those seen …