Biochemistry, Biophysics, and Structural Biology Commons^™

Developing A Biocatalytic Toolbox To Aid In Understanding Nucleoside Antibiotics, Jasmine Brianna Woods

Theses and Dissertations--Pharmacy

Antibiotic resistance happens when bacteria develop the ability to survive medications that normally terminate them. Instead, these super germs are able to survive in the body and produce a community of antibiotic resistance germs which can cause human fatalities. It is important to discover and develop new compounds and molecules that will improve this clinical obstacle. This research focused on analyzing the biosynthesis that incorporates distinctive chemical characteristic of various nucleoside antibiotics, ß-hydroxy amino acids and α-methyl-amino acids. ß-hydroxy amino acids and α-methyl-amino acids are considered an important class of industrially useful compounds, particularly for pharmaceutical development, and are found …

Impact Of Sample Conditions On Dna Phosphodiester Backbone Bi/Bii Conformational Equilibrium Dynamics, Autumn C. Pilarski

Graduate Theses/Dissertations

DNA damage, such as single base lesions and mismatches, is highly prevalent within cells. If these DNA damage events are not repaired, they could lead to mutations and thus disease and cancer. Intricate repair mechanisms are in place to fix these damage events, one such being Base Excision Repair (BER) and associated enzyme: Thymine DNA Glycosylase (TDG). The first step of this repair process, recognition of the lesion by TDG, is not well understood. The following thesis presents results to better understand the fundamental biophysical question of how a DNA lesion within a mismatch context is recognized in a million …

Investigating Mirna Regulation Of The Human Apobec3 Enzymes, William Dietrich

All Graduate Theses, Dissertations, and Other Capstone Projects

The human apolipoprotein B mRNA editing enzyme catalytic polypeptide 3 (APOBEC3, A3) are a family of proteins consisting of seven enzymes, A3A, B, C, D, F, G and H, which function as cytosine deaminases. The enzymes’ purpose in the cell is to mutate viral DNA during infection hindering or stopping replication of viruses such as human papillomavirus, herpes simplex virus, and HIV-1. Several of the A3 enzymes have also been implicated in contributing to cancers such as head and neck and breast cancers by mutating cellular genomic DNA, making the ability to control A3 expression an attractive target for cancer …

Novel Amino Acids Dictate Differences In Sivmac239 And Hiv-2 Rod9 Vpx Cellular Localization, Hunter D. Mayhew

All Graduate Theses, Dissertations, and Other Capstone Projects

Vpx is a protein encoded by Human Immunodeficiency Virus Type 2 (HIV-2) and specific Simian Immunodeficiency Viruses (SIVs) that is essential for successful infection of non-dividing myeloid cells. Vpx facilitates viral replication by trafficking the viral genome into the nucleus of infected cells and targeting the primarily nuclear innate immune protein SAMHD1 for proteasomal degradation. Considering that these activities occur at the nucleus, we hypothesized that Vpx nuclear localization would be tightly correlated with these functions. To assess this, site directed mutagenesis in combination with confocal microscopy or Western Blotting analyses were utilized to evaluate the determinants of nuclear accumulation …

Investigation Of Mechanical Regulation On Stat3 Activity And Mmp Production, Jaxson R. Libby

Honors Theses and Capstones

Transcription factor, STAT3, is inappropriately expressed in cancer cells, and has contrasting activation in 2D versus 3D microenvironments. 2D plates are often used for drug screening and do not always recapitulate in vivo responses. To combat inaccurate 2D drug studies, a 3D hydrogel was created to support the growth of cancer cells into a tumor-like environment. The hydrogel consists of a biocompatible dextran homopolysaccharide, cell adhesion RGD sequences, and crosslinker MMP labile peptides. A pH dependent reaction couples the RGD sequences to dextran then the polymers are crosslinked into a gel. Crosslinking is accomplished using terminal cysteine peptide sequences, allowing …

Molecular Mechanisms Of Wild-Type And Mutant Prion Formation, Daniel J. Walsh

Dartmouth College Ph.D Dissertations

Prion diseases are a class of infectious neurodegenerative disorders which affect humans and many other mammalian species. The causative agent is a unique pathogen known as a prion or PrPSc, a misfolded form of a host-encoded glycoprotein which replicates by templated conformational change. Distinct strains of prions with unique phenotypic and pathologic presentations appear to be encoded by subtle conformational changes within the misfolded protein. While the general manner of prion transmission is known, our detailed understanding of these mechanisms remains incomplete, limiting efforts for the discovery or design of therapeutic treatments for these fatal diseases. In vitro synthesis of …

Interactomics And Targeted Protein Degradation For Kinase Substrate Discovery, Juan C. Mercado Del Valle

Dartmouth College Ph.D Dissertations

Reversible phosphorylation is one of the most important post translational modifications that has allowed us as a species to quickly adapt to changing molecular environments due to external stimulation. This process is only capable through the activity of kinases to carry out the targeting of specific substrates defined by their recognition motif allowing for selective phosphorylation and activation and inactivation of distinct pathways as well as other changes that permit cell survival. By being so important for the maintenance of the cells disruption often leads to worsening of the cells, leading to various diseases like cancer, immunological and neurodegenerative disorders. …

Specialized Metabolism In Retina, Retinal Pigmented Epithelium, And Testis, Siyan Zhu

Graduate Theses, Dissertations, and Problem Reports (ETD)

The retina and its neighboring retinal pigmented epithelium (RPE) are high energy-demanding and metabolically active tissues with specialized and complementary metabolism. They are metabolically interdependent and impact each other’s viability. Interestingly, many of the metabolic features in the retina and RPE are shared with the testis. For example, testis is also energy costly due to continuous sperm differentiation and it has similar metabolic inter-dependence between different testis cells. Both the retina and testis are vulnerable to mitochondrial metabolic impairments.

We conducted three research projects to understand 1) the nutrient utilization and communication in retina and RPE; 2) The profiling of …

Multilevel Computational Investigation Into The Catalytic Mechanisms Of Matrix Metalloproteinase-1 And Fat Mass And Obesity-Associated Enzyme, Ann Varghese

Dissertations, Master's Theses and Master's Reports

Enzymes are biological macromolecules, typically proteins, that efficiently accelerate the rate of chemical reactions. Their remarkable catalytic power plays a vital role in essential processes across all kingdoms of life. Nowadays, computational chemistry methods provide valuable insights into enzymatic functions aiding our understanding of biological processes and providing advancements in fields such as biomedical sciences, biomimetic catalysis, drug design and biotechnology. This dissertation employs multilevel computational chemistry methods to investigate the structure-function relationships and the catalytic mechanisms of two metalloenzymes -Zn(II)-dependent matrix metalloproteinase-1 (MMP-1) and non-heme Fe(II)/2-oxoglutarate (2OG) dependent fat-mass and obesity-associated (FTO) enzyme. Chapter 2 explores the role of …

Multiscale Molecular Modeling Studies Of The Dynamics And Catalytic Mechanisms Of Iron(Ii)- And Zinc(Ii)-Dependent Metalloenzymes, Sodiq O. Waheed

Dissertations, Master's Theses and Master's Reports

Enzymes are biological systems that aid in specific biochemical reactions. They lower the reaction barrier, thus speeding up the reaction rate. A detailed knowledge of enzymes will not be achievable without computational modeling as it offers insight into atomistic details and catalytic species, which are crucial to designing enzyme-specific inhibitors and impossible to gain experimentally. This dissertation employs advanced multiscale computational approaches to study the dynamics and reaction mechanisms of non-heme Fe(II) and 2-oxoglutarate (2OG) dependent oxygenases, including AlkB, AlkBH2, TET2, and KDM4E, involved in DNA and histone demethylation. It also focuses on Zn(II) dependent matrix metalloproteinase-1 (MMP-1), which helps …

Mitochondrial Division: Synergizing In Mitochondrial Divisome, Ao Liu

Dartmouth College Ph.D Dissertations

Mitochondria are the energy factories of the cell. The dynamic nature of cells demands routine changes in mitochondrial morphology by fusion and division. The dynamin GTPase Drp1 is a central mitochondrial division protein, driving constriction of the outer mitochondrial membrane via oligomerization. At least four regulatory factors control Drp1 activity on the outer mitochondrial membrane (OMM): 1) receptor proteins (Mff, MiD49, MiD51, and Fis1); 2) actin filaments; 3) the mitochondrial phospholipid cardiolipin (CL); and 4) Drp1 post-translational modifications, of which two phosphorylation sites (S579 and S600) are the most well studied. However, the molecular mechanism of how these factors work …

Identification Of A Dna Polymerase Alpha Gene Sequence In Thermomyces Lanuginosus Fungus, Nathan Williams

Honors Program Theses

With cell growth being the main focus of our research, we chose to study DNA polymerase alpha. DNA polymerase alpha is likely to be involved in cell growth as it is the enzyme that starts DNA replication. Control of this enzyme might lead to decreased cell growth in cancer or increased cell growth in damaged spinal cord tissue. We chose the thermophilic fungus Thermomyces lanuginosus for the study of the enzyme due to the ability to compare the enzyme’s activity during fungal growth at different temperatures. Thermomyces exhibits rapid growth at high temperatures and slow growth at low temperatures. Studying …

Recent Insights On The Conformational Changes, Functionality, And Physiological Properties Of Plant-Based Protein–Polyphenol Conjugates, Mehnaza Manzoor, Zaria Fozonne Ngabou Tchameni, Zuhaib F. Bhat, Amit K. Jaiswal, Sundeep Jaglan

Articles

Plant proteins are promising sources of nutrition with enhanced health benefits due to their interaction with bioactive compounds like polyphenols. These interactions can form protein–polyphenol complexes with diverse properties and applications in the food, nutraceutical, and pharmaceutical industries. To exploit the potential of these conjugates, it is essential to understand how they are formed, characterized, and delivered. Various techniques such as spectroscopy, thermodynamics, and molecular docking simulations can reveal the mechanism and outcomes of protein–polyphenol binding. Moreover, the surface modification of protein–polyphenol conjugation can enhance the pharmacological effects of different drug molecules and enable their targeted delivery to specific tissues …

Biogeography Of Special Metabolites Produced By Ant-Associated Bacteria, Katherine Hansen

Scripps Senior Theses

There is an urgent and growing need for novel antibiotics with the growing prevalence of antibiotic-resistant pathogens. Ecologically-guided discovery is a strategy that focuses on how and where specially evolved metabolites such as antibiotics are used in nature. This strategy reveals unique active molecules with potential for human use. An unexplored niche with great potential for antibiotic discovery exists with Southwestern fungus-farming Trachymyrmex ants and their Actinobacteria symbionts. In exchange for nutrients from the ant, the ants’ bacterial symbiont produces antifungal molecules that protect the ants’ fungal cultivar from invasion by pathogenic microorganisms. They also produce antibacterial molecules to protect …

Determination Of The Effects Of Added Methionine On The Toxicity Of Platinum Drugs In Saccharomyces Cerevisiae, Kassidy Owens, Jonathan White

Longwood Senior Thesis Proposal

Platinum (Pt) drugs are used in about half of all anticancer treatments. A common way to study Pt drugs is by using S. cerevisiae (brewer’s yeast) as a model cellular organism. One of the most commonly-used strains of yeast is BY4741, which is auxotrophic for (cannot synthesize) several small-molecule nutrients, including the amino acid methionine. Therefore, methionine must be supplemented in the cell culture medium. Interestingly, it is known that methionine can react with Pt compounds, including Pt drugs. Methionine-supplemented media continues to be used to study Pt drugs in yeast, especially BY4741, yet the potential for methionine to interfere …

Investigating Visinin-Like Protein 1 And Ubiquitinated Visinin-Like Protein 1 As Mild Traumatic Brain Injury Biomarkers, Yueming Wu

Theses and Dissertations--Chemistry

Traumatic brain injury (TBI) continues to be a significant cause of morbidity and mortality worldwide. Despite significant progress in understanding the complex pathophysiology of TBI, the underlying mechanisms remain poorly understood. The primary brain damage is acute and irreversible. However, secondary brain injuries often develop gradually over months to years, creating an opportunity for critical therapeutic interventions. In the past decade, research on TBI biomarkers has seen significant progress. This progress has been driven by the diverse nature of TBI pathologies and the challenges they present for evaluation, management, and prognosis. TBI biomarker proteins resulting from axonal, neuronal, or glial …

College Of Natural Sciences 2022 Year-End Publication, College Of Natural Sciences

College of Natural Sciences Newsletters and Reports

This is the 2022 issue of the annual College of Natural Sciences year-end publication.

Contents:
[Page] 2 Dean's message
[Page] 3 Department highlights
[Page] 4 Overview of Bold & Blue Campaign
[Page] 5 Dr. Edward Hogan recognition & endowment
[Page] 6 Career milestones
[Page] 7 Student travel and research
[Page] 8 $11 million COBRE grant
[Page] 9 Professional Science Masters & Research highlights
[Page]10 Outreach highlights throughout the state
[Page] 11 2022 events recap – join us in 2023!
[Page] 12 Updates on our VR initiative
[Page] 14 Overview of awards and recognitions from 2022

Exogenous Factors That Impact Huntingtin Aggregation, Adam Skeens

Graduate Theses, Dissertations, and Problem Reports (ETD)

While expansion of a polyglutamine (polyQ) domain is the immediate cause of huntingtin (htt) aggregation associated with Huntington’s Disease (HD), other cellular factors modify aggregation. These include interactions with cellular membranes, protein biding partners, molecular crowding, and proteinaceous seeds. Here, two important factors are biophysically characterized: 1) the interaction of htt with endomembranes and 2) proteinaceous seeds obtained from a variety of htt-derived peptides. In the first project, the aggregation of htt at bilayer interfaces and in the presence of divalent cations was investigated. A major cellular factor implicated in altered htt aggregation is the binding of lipids. Furthermore, the …

Elucidating Mechanisms Of Proteasome Modulation By Small Molecules To Treat Neurodegenerative Diseases And Cancer, Janelle Joo Yee Chuah

Graduate Theses, Dissertations, and Problem Reports (ETD)

Maintaining protein homeostasis, or proteostasis, is crucial for cellular function, and protein degradation through the proteasome plays a pivotal role in this process. Dysregulation of the proteasome can lead to proteostasis collapse and has been linked to the development of neurodegenerative diseases and cancers. Neurodegenerative diseases often exhibit proteasome impairment, whereas proteasome upregulation is frequently observed in cancer. Although the use of proteasome inhibitors as a pharmaceutical approach has shown success in certain cancers, it has yet to demonstrate efficacy in neurodegenerative diseases due to the absence of drug-like small molecules capable of effectively reversing proteasome impairment and/or activating the …

Dna Methylation And The Response To Infection In Introduced House Sparrows, Melanie Gibson

College of Graduate Studies: Theses & Dissertations

Epigenetics is the study of molecular modification of a genome without changing its base pairs. The most studied type of epigenetic mechanism is DNA methylation, which is capable of turning a gene “on” or “off.” Epigenetic potential is the capacity to which an individual can have methylation on its genome. The more CpGs available, the greater the epigenetic potential. In invasive species, genetic variation has been observed to be paradoxical: not much of it exists on a genomic level, but epigenetically, phenotypic variation can occur. The focus on shift in gene expression in this study is on Toll-Like Receptor 4 …