Molecular Biology Commons^™

N-Allylation Of Secondary Amides With Unsymmetrical Propionates, Remi Graff

Honors Theses

The combination of trimethylsilyl trifluoromethanesulfonate (TMSOTf) and Et3N promotes the N-allylation of 4-methoxyacetanilide 2 with unsymmetrical propionates 1 (eq 1). The amide substrate is believed to undergo conversion to a nucleophilic silyl imidate in the presence of TMSOTf and the amine base, which concurrently promotes carbocation formation in the same flask through the loss of trimethylsilyl propionate, leading to N-allylation of the amide. A range of unsymmetrical propionates, accessed by varying the R and R’ substituents, react efficiently in this one-pot process with yields ranging from 44% to 99%, affording regioselective ratios of up to >20:1 through formation of regioisomers …

Development Of A Python Pipeline For The Inference Of Selection In Human Genomes And Applications To Adh1b*2, Aine Macdermott

Honors Theses

Human evolutionary genomics provides an avenue to understand how genetic variation has been impacted by the environmental pressures of the past, revealing how selective pressures impacted past populations and contributed to present-day biological diversity. In this thesis, I describe the construction of a Python-based computational pipeline designed to automate and integrate multiple analyses of positive selection across worldwide population datasets, including derived allele frequency calculation, haplotype-based tests of selection, RELATE-based genealogical inference, and CLUES2-based temporal modeling. By automating file preparation, format conversion, job submission, result aggregation, model comparison, and visualization, this pipeline streamlines the data interpretation process, and shifts focus …

Exploring Phosphoregulation Of Myo3a Using Quantitative Fluorescence Image Analysis In Cos7 Cells, Vu Hao Minh Nguyen Phan

Honors Theses

Myosin 3A (MYO3A) is an unconventional myosin involved in the formation and maintenance of hair-cell stereocilia of the sensory epithelia in the inner ear. The kinase domain has been implicated in phosphoregulation of MYO3A activity through intermolecular autophosphorylation. Previous studies using mass spectrometry identified two potential phosphorylation sites in the motor domain. To investigate the regulatory roles of these sites, we generated glutamic acid point mutations in our mchr-MYO3AΔK construct to mimic phosphorylation and assayed the constructs for their ability to tip-localize and influence filopodial density via transfection into COS7 cells. The phosphomimic constructs were less able to generate filopodia …

Development And Functional Characterization Of Carbon Nanodot-Peptide Conjugates For The Treatment Of Bone Disease, Abigail Ali

Honors Theses

Carbon nanodots (CDs) synthesized from carbon nanopowder under acid oxidative conditions have unique bone-bind properties that could be exploited for theranostic purposes. In the zebrafish vertebrate model system, CDs bind to bone with high affinity and specificity, they don’t appear to bind to other tissues and they do not affect the bone physiology or animal viability. Thus, carbon-derived CDs could be developed for the delivery of pharmacological agents to bones to treat diseases such as osteoporosis. Biologicals such as peptides, proteins and antibodies are a new and exciting class of pharmacological agents that have been successfully used in treating complex …

Development Of A Diaryl Oxazole-Based Cleavable Linker For Peptides, Evan Wolff

Honors Theses

The development of new cleavable linkers increases the diversity of compatible conditions for peptide discovery platforms. Potential applications for these linkers include high-throughput pharmaceutical candidate screening when utilized in Peptide Encoded Libraries (PELs). This thesis describes the development of a bifunctional diaryl oxazole-based cleavable linker that may be incorporated into compounds through Solid-Phase Peptide Synthesis (SPPS). This oxazole-based linker may be rapidly cleaved by cerium ammonium nitrate in aqueous conditions and is compatible with most natural amino acids and a variety of unnatural amino acids. This linker represents the first single-electron oxidant labile linker described to our knowledge and it …

Functionalized Gold Nanoparticles And Halogen Bond Interactions With Neonicotinoid Pesticides, Molly Mccuen “Mackey” Sherard

Honors Theses

Neonicotinoid (NN) pesticides have emerged globally as one of the most widely used agricultural tools for protecting crops from pest damage and boosting food production. Unfortunately, some NN compounds, such as extensively employed imidacloprid-based pesticides, have also been identified as likely endangering critical pollinating insects like honey bees. To this end, NN pesticides pose a potential threat to world food supplies. As more countries restrict or prohibit the use of NN pesticides, tools are needed to effectively and quickly identify the presence of NN compounds like imidacloprid on site (e.g., in storage areas on farms or pesticide distribution warehouses). This …

Cd46 Isoforms And Viral Receptor For Adenovirus Type 64d, Corina Stasiak

Honors Theses

Adenovirus Type 64 (Ad.64) belongs to the adenovirus subgroup D, which causes epidemic keratoconjunctivitis (EKC), otherwise known as viral pink eye. There is currently no known effective treatment for EKC. Membrane Cofactor Protein (CD46) is an integral membrane glycoprotein that, in previous studies, has been identified as a protein receptor for the closely related Ad.37. It has been determined that Ad.64 uses CD46 as a receptor on the cell surface in HeLa cells. CD46 is alternatively spliced when expressed to have different isoforms of interest, including the BC and C isoforms. Certain cell types, like A549 lung carcinoma cells, express …

Cd46 Is A Protein Receptor For Human Adenovirus Type 64, Alexander Michael Robertson

Honors Theses

Adenoviruses are important gene delivery vectors and causative agents for a variety of human diseases such as the common cold and gastrointestinal infections. Human adenovirus type 64 (Ad64; formerly 19c) and type 37 are associated with epidemic keratoconjunctivitis. Based upon its high homology and similar disease tropism to Ad37, we hypothesized that Ad64 would have the same protein receptor, CD46 (membrane cofactor protein), as Ad37. We show that a recombinant Ad64 containing an enhanced Green Fluorescent Protein transgene (Ad64.eGFP) enters Chinese hamster ovary cells expressing human CD46 (CHO-CD46) on the surface. Entry into human cervical carcinoma (HeLa) cells is increased …

Structural Phylogenetics Of A Family Dna Polymerases, Yagmur Bingul

Honors Theses

The transition from the RNA to the DNA world stands as an important event, demanding the emergence of enzymatic activities for DNA precursor synthesis, retro-transcription of RNA templates, and replication of single and double-stranded DNA molecules. The distribution of protein families associated with these activities across the three domains of life—Archaea, Eukarya, and Bacteria—adds layers of complexity to the narrative. While Archaea and Eukarya often share similar protein structures, structural biology shows homologous, but distinct, structures in Bacteria. On the other hand, viral polymerases emerge as a crucial part of genome replication and transcription. Their versatility, including RNA-dependent RNA polymerase, …

Heterocycles As Peptide-Based Cleavable Linkers, John Blobe

Honors Theses

As cancer cases continue to rise, the need for advancing the treatment options for cancer is ever increasing. Current cancer therapeutics, while effective at treating localized cancers and a fraction of advanced cancers, generally lack the specificity needed to target more advanced cancers. Recent advancements in cancer treatments have leveraged antibodies to target certain cancers. A class of drugs that utilize antibodies to deliver anti-cancer therapy preferentially to cancer cells, termed antibody-drug conjugates (ADCs), have been quite effective in treating certain advanced forms of certain cancers. These ADCs could be more effective if they could allow for the facile release …

Diaryl Oxazoles As Cleavable Linkers For Drug Discovery Platforms, Elizabeth Taggart

Honors Theses

Within the field of medicine and pharmacology, discovering small molecule or biologic based molecules with therapeutic potential is a difficult task. Current methods involve individually screening hundreds of compounds on a potential target biomolecule, and recent technologies have explored peptide encoded libraries (PELs) as a means of making this screening process more high-throughput. These libraries produce a large number of small molecule drug candidates each conjugated to a unique peptide fragment, functioning as a barcode. Analysis of PELs requires the capture of hit small molecules and the subsequent release of their peptide tags; however, current approaches are limited in their …

Role Of Cdx4 And Sp5l In Zebrafish Development, Wesley Tsai

Honors Theses

The Caudal Type Homeobox transcription factors cdx are a family of genes found in vertebrates that regulates body regionalization and anterior-posterior patterning. They are also responsible for regulating axial elongation, but the mechanisms behind this behavior are not known. Previous studies in mouse embryonic stem cells have shown that the cdx genes are necessary for upregulating the gene sp5 which may be linked to axial elongation. Sp5 is a zinc-finger transcription factor belonging to the specificity protein (sp) family. Our group has used in-situ hybridization experiments on zebrafish embryos to show that sp5-like (sp5l) is transcribed within tailbud tissues that …

Bryophytes Of Goochland County, Virginia, Mikayla Quinn

Honors Theses

Bryophytes are non-vascular land plants that include mosses, liverworts, and hornworts. Although easier to overlook because of their smaller size, bryophytes are a fundamental part of the ecosystem. As such, maintaining record of their biodiversity is important. Yet, records of bryophyte species in Goochland County, VA were low compared to more thoroughly documented counties such as Prince Edward County. This study expands the documentation of bryophyte flora and presents a checklist of bryophyte species found Virginia’s Goochland County from 2020-2023. Fieldwork conducted at public and privately-owned properties throughout the county between January 2020 and March 2023 yielded 702 specimens that …

Investigating The Helicase Activity Of Methylated Vs Unmethylated Ded1, Hannah Lukow

Honors Theses

Ded1 is an RNA helicase protein of the DEAD-box subfamily in eukaryotic organisms (Sharma & Jankowsky, 2014) which can act as an activator or initiation factor, during translation (Hilliker et al., 2011). Ded1 has several functions in yeast including assembly of translational initiation factors, scanning the mRNA for the start codon, and unwinding any double stranded segments of mRNA with its helicase ability. Ded1 was discovered to be methylated at four arginine sites in vivo (Low et al., 2013), with a fifth methylation site being discovered recently (Low et al., 2020), however the purpose of such post-translational modifications is still …

The Role Of Cerium(Iii) In Bacterial Growth And The Microbial Transformation Of Aromatic Hydrocarbons, Shruti Sathish

Honors Theses

Biofilms are communities of surface-attached bacterial cells encased in an exopolymeric matrix. In this state, they are more resistant to antimicrobial treatment and can have adverse effects in medical, agricultural, and industrial settings. Whereas, as biocatalysts, biofilms from nonpathogenic bacteria enhance their performance and stability in catalysis. Unfortunately, there are several challenges when using bacteria in organic transformations due to their complex cellular chemistry. Trivalent lanthanide metals were discovered to serve regulatory roles in some bacterial catalytic processes, including those of Pseudomonas putida KT2440 (P. putida), a non-infectious Gram-negative bacterium. The main goal of our research is to use cerium(III) …

Halogen Bonding: A Computational Chemistry Investigation Of The Interaction Between Thyroid Hormone And Deiodinase, William Rice

Honors Theses

Halogen bonding is a noncovalent interaction that continues to garner interest among the scientific community. Investigation of halogen bonds in biological contexts typically revolves around rational drug design for developing therapeutics. However, halogen bonding may be occurring naturally in our body every day. Thyroid hormone and its regulating enzyme, iodothyronine deiodinase, show promising results for a halogen bonding interaction that happens during catalysis. Prior work has examined the interaction between the iodine of thyroid hormone and the selenium of iodothyronine deiodinase. However, this study is the first of its kind to use computational chemistry methods to analyze the halogen bond …

The Socioeconomic & Environmental Factors Influencing Prevalence Of Zoonotic Pathogens In Rats: A Meta-Analysis, Katelyn Wing

Honors Theses

Background/Question/Methods

Global rat populations are increasing at an alarming rate across the world. In turn, this increases the risk of human-rat interactions and the potential spread of zoonotic pathogens and parasites. Rats are the second most common host of disease and can have detrimental effects in urban ecosystems. Rattus rattus and R. norvegicus are the two most abundantly distributed species of rats and are the target organism for this study. The aim of this study is to understand the connection between environmental and socioeconomic factors that influence the rate of zoonotic disease in rats. We developed two hypotheses to gain …

The Importance Of Ile716 Toward The Mutagenicity Of 8-Oxo-2’-Deoxyguanosine With Bacillus Fragment Dna Polymerase, Michelle L. Hamm, Anarosa A. Garcia, Rachel Gilbert, Manavi Johri, Miranda Ricart, Samantha L. Sholes, Laura A. Murray-Nerger, Eugene Y. Wu

Biology Faculty Publications

8-oxo-2’-deoxyguanosine (OdG) is a prominent DNA lesion that can direct the incorporation of dCTP or dATP during replication. As the latter reaction can lead to mutation, the ratio of dCTP/dATP incorporation can significantly affect the mutagenic potential of OdG. Previous work with the A-family polymerase BF and seven analogues of OdG identified a major groove amino acid, Ile716, which likely influences the dCTP/dATP incorporation ratio opposite OdG. To further probe the importance of this amino acid, dCTP and dATP incorporations opposite the same seven analogues were tested with two BF mutants, I716M and I716A. Results from these studies support the …

Evaluating A Culprit: A Review Of The Biochemical Mechanisms Of Non-Celiac Gluten Intolerance, Callie Cinque

Honors Theses

Non-Celiac Gluten Intolerance (NCGI) has evaded biological and chemical mechanisms since it was first reported in 1978. Celiac Disease, a multi-system immune mediated disorder has long served as the most similar counterpart to NCGI. Less cases of celiac disease are going undiagnosed reflecting an improvement on sensitive and decisive diagnostic tools. However, NCGI has been significantly growing as a diagnosis over the past decade with little match or similarity to the markers found in celiac disease patients. Critical evaluation of NCGI theories, experimentation, and existing hypotheses is necessary. This review seeks to synthesize multiple disciplines of gluten research and enhance …

Application Of Β-Chloroenals: One-Pot Syntheses To Create Highly Variable, Functional, And Biologically Interesting Molecules, Julia Powell Siewert

Honors Theses

Pyrroles and pyrazoles are privileged structures which provide a molecular framework found in many different classes of bioactive compounds, thus rendering their syntheses useful in pharmaceutical drug development. Additionally, being able to selectively create these molecules with interesting substituents allows for different pharmacological and biological activities, such as antitumor and antibiotic effects. Our group has used β-chloroenals in the application of many different unique synthetic strategies in the past, and here I show that chloroenals can be used to synthesize novel 1,2,5 trisubstituted pyrroles as well as 1,5 di- and 1,4,5 trisubstituted pyrazoles in fewer steps and with milder conditions …

The Effects Of Signaling Molecules To Agrobacterium Tumefaciens Tumorigenesis At Plant Wound Sites, Nicole Walker

Honors Theses

Agrobacterium tumefaciens can live independently within soil before infecting its host (McCullen and Binns, 2006). The bacterium infects the plant through the rhizosphere, an area of soil along the plant root surface which contains microorganisms, making up the “external metabolome” (Bais et al. 2006). As these bacteria live in the rhizosphere, they are exposed to a multitude of chemical signals. These chemical signals include several conditions that must be met before the virulence machinery is expressed. These conditions include signaling from phenols and sugars as well as low PO4 levels and low pH. Upon wounding, sugars and phenols are released …

Computational Studies Of Paradifluorobenzene Cations And Hydrogen Cyanide Molecule, John C. Rowe Iv

Honors Theses

Polycyclic aromatic hydrocarbons (PAHs) are hypothesized to comprise a significant portion of interstellar carbon identified from the Diffuse Interstellar Bands (DIBs). Gas phase cation-molecule reactions between compounds that previously existed as weakly bound species provides the best explanation for the emergence of PAHs in the interstellar medium (ISM). In this work, we use computational methods to characterize one of these weakly-bound systems. We discovered that intramolecular charge distribution (calculated using the Natural Population Analysis) dictate the complexes formed between a paradifluorobenzene cation and either one or two HCN molecules. Additionally, the relative stabilities of the complexes and the binding energies …

Characterization Of Catecholamine Receptors And Transporters In Murine Macrophages, Elizabeth Gonye

Honors Theses

Macrophages are a critical part of the immune response. When circulating monocytes move into tissues they differentiate int macrophages to mount the first line of defense against pathogens.

Calcium (Ii) Catalyzed Nitrone Additions, Elizabeth A. Congdon

Honors Theses

Calcium(II) complexes have be shown to be successful catalysts for nitrone reactions. The addition of n-­‐methyl and n-­‐phenyl nitrones to donor-­‐acceptor cyclopropanes was achieved with calcium triflate (Ca(OTf). Differentially substituted tetrahydro-­‐1,2-­‐oxazines were synthesized in good to excellent yields. Calcium triflate was also found to catalyze the addition of silyl enol ethers to n-­‐phenyl nitrones along the Mukaiyama-­‐Mannich addition pathway. B-­‐amino carbonyls were synthesized from a variety of substituted nitrones. Bulky and cyclic silyl enol ethers were also found to be reactive, the products of which were isolated in good to excellent yields.

Impact Of Vector Range Expansion On Pathogen Transmission Dynamics Of Lyme Disease In Southwestern Virginia, Bishan Bhattarai

Honors Theses

Blacklegged ticks, Ixodes scapularis is the primary vector of Lyme disease in eastern United States. Borrelia Burgdorfei, the etiological agent of Lyme disease is transferred by ticks of Ixodes species. In recent years, its congener, Ixodes affinis has been expanding its range northwards from its southern population. We were interested in studying how the introduction of this new vector affected the interaction between the pathogen genotype and the host. We hypothesized that differential host use by I. affinis and I. scapularis would partly explain observed differences in B. burgdorferi infection prevalence and genotypic structure in southeastern Virginia. The result …

Isolation Of Microbial Nrps And Pks Gene Clusters For Natural Product Isolation, Danielle N. O'Hara

Honors Theses

Greater than 99% of microbes living in the environment are uncultivable due to their complex nutrient and temperature requirements for growth. These microorganisms present a potential source of natural products that could be developed for biotechnological and pharmaceutical uses. Microorganisms with phosphopantetheinyl transferase (PPTase) activity are of high interest due to the role PPTase plays in activating non-ribosomal peptide synthetase (NRPS) and polyketide synthase (PKS) gene clusters. These gene clusters produce multi-enzymatic, multi-domain megasynthases that produce complex natural products utilized by the host organism for selective advantages. This study isolated genomic DNA from soil samples collected from the University of …

An Nmr-Guided Approach To The Isolation Of Secondary Metabolites From Nrps And Pks Gene Clusters, Connor Craig

Honors Theses

Secondary metabolites continue to offer a promising source of novel chemical entities with therapeutic bioactivities. Our research aims to isolate secondary metabolites produced by non-ribosomal peptide synthetase (NRPS) and polyketide synthase (PKS) constructs. A metagenomic library was created from the marine bacterium Pseudoalteromonas sp., which was isolated from the Chesapeake Bay sponge Halichondria bowerbanki. Using a functional screen for PPTase activity we were able to identify colonies that contained NRPS and PKS gene clusters. Cultures of this microbe have been produced and analyzed using a combination of chromatography and 1H, 13C, HMBC, HSQC, COSY, AND NOESY NMR spectra. …

Development Of A Genetic Over-Expression System For The Freshwater Sponge Ephydatia Muelleri, Joe Walsh

Honors Theses

The aim of this work is to develop an over-expression system for Ephydatia muelleri. Preliminary work by Klaske Schippers (Schippers, 2013) showed sponges were induced to transcribe reporter genes driven by the widely used cytomegalovirus promoter (CMV). Building off Schippers work, newly identified native Ephydatia promoters were identified from the genome and verified to drive expression ofreporter genes. Validated over-expression vectors and transfection technology will allow researchers around the world who are working with this organism to ask questions about cell specification, gene regulation and animal development.

Formyl Group Activation Of Bromopyrrole Suzuki Cross-Coupling: Application To A Formal Synthesis Of Lamellarin G Trimethyl Ether, Andrew Harrison

Honors Theses

Many biologically interesting compounds have been isolated from marine natural products, many of which contain characteristic pyrroles. Compounds such as polycitones, storniamides, ningalins, and lamellarins have been of particular interest for synthesis due to their vast pharmaceutical potential including the ability to fight tumors as well as induce cytolysis of drug resistant cancer cell lines. Previous studies on the synthesis of Lamellarin G trimethyl ether by the Gupton Group have relied upon vinylogous amide derivatives as building blocks.2 A new pathway utilizing a formylated pyrrole ring provides an interesting method for the synthesis of Lamellarin G trimethyl ether. Regioselective Suzuki …

A Conservative Isoleucine To Leucine Mutation Of Klentaq1 Dna Polymerase 1 Induces Conformational Change For Cold-Sensitive Phenotype, Emma Caroline Materne

Honors Theses

Polymerase Chain Reaction (PCR) typically employs the Taq or Klentaq1 DNA polymerase from Thermus aquaticus to elongate short sequences of DNA during DNA amplification. Both Taq and Klentaq1 retain activity at room temperature. During assembly of PCR at room temperature, the activity of Taq and Klentaq1 can result in spurious products due to elongation of primers bound to non-target sequences. A mutation of isoleucine to leucine at position 707 of Klentaq1 results in slowing of the enzyme at room temperature without compromising the fidelity of the enzyme. To understand how a mutation over 20Å from the active site can affect …