Biochemistry, Biophysics, and Structural Biology Commons^™

Synthesis Of An Ideal Inhibitor For The Lpxc Enzyme, Taejun Lee

Honors Theses

Due to the growing need of antibiotics in modern day medicine, this study attempts to apply a method of medicinal chemistry that would create a novel inhibitor for a lesser known target of gram negative bacteria, the LpxC enzyme. This study proposes that a synthetic plan which consists of combining components of different molecules would create a more effective inhibitor. These components include a binding group for the active site of the enzyme, a hydrophobic chain which has been shown to interact with an allosteric site on the LpxC enzyme, and the isoxazoline ring which interacts with the zinc ion. …

Exploration Of Thiol-Michael Addition Bioconjugation To Extend Polymers Of A Protein-Based Hydrogel, Elaine Wallin Smith

Honors Theses

Hydrogels have been explored for many biomedical applications, including targeted, in situ drug delivery to avoid the negative side effects associated with systemic delivery. In our work, we are exploiting the high affinity, calcium-dependent binding between calmodulin and its target peptides to create a biomaterial for in situ, extracellular drug delivery. Genes were engineered to make two protomers, Calmodulin Collagen-Like Protein (CCLP) and Peptide Collagen-Like Protein (PCLP), that will spontaneously self-assemble in situ due to the high Ca2+ concentration in the extracellular space and provide tunable, targeted drug delivery in a biocompatible hydrogel. One important factor that would dictate the …

Benchmark Structures And Harmonic Vibrational Frequencies Of Hydrated Halide Ions: X– (H2o)N, X = F, Cl, Br, And I (Where N = 1 – 4), Caroline Anne Rader

Honors Theses

This study extends our efforts to generate benchmark structures and harmonic vi- brational frequencies from neutral hydrogen bonded clusters to solvated ions. The analytical gradients and Hessians developed for the N-body:Many-body integrated QM:QM method facilitate the computation of benchmark-quality properties near the CCSD(T) complete basis set limit. In this work, a series of solvated halide ion sys- tems (X−(H2O)n clusters, where X = F, Cl, Br and I and n = 1 to 4) is being characterized with the MP2 and 2-body:Many-body CCSD(T):MP2 (2b:Mb) meth- ods. For n ≥ 2, the latter technique uses the high-level CCSD(T) method to evaluate …

Lost In Translation: Challenges And Solutions To Language Barriers In Healthcare In Mississippi, Galina Ostrovsky

Honors Theses

Language barriers can impede access to healthcare and compromise quality of care for limited English proficiency (LEP) patients. Although a rights-based framework would suggest and federal mandates require healthcare facilities to provide language access services, multiple factors result in the persistence of language barriers in healthcare. As the literature review shows, these factors include limitations in policy, enforcement, standardization, resources, and ability to recruit and retain professional interpreters. This thesis uses a multi-method case study entailing Mississippi in general and information from two specific sites, a rural Delta county and an urban central county, to assess the issue of language …

Preparation Of A Perylenebisimide Acceptor With Serinol And Nonadecyl-Swallowtail Imides For Use In Molecular Rectification, Tarrah Frederick

Honors Theses

Several attempts were made to add 2-amino-1,3-propanediol to the acceptor perylene monoanhydride (PMA). The theoretical product, N-(10-nonadecyl)-N'-(1,3-dihydroxypropan-2-yl)perylene-3,4,9,10-bis(dicarboximide), is intended for use in unimolecular rectification because the perylenebisimide core is classified as a good acceptor due to its high electron affinity. Rectification usually utilizes donor-σ-acceptor molecules, whose localized orbitals permit electron transfer when placed between metal electrodes of asymmetric voltages. However, according to an “asymmetric rectification” analysis, an electron can pass from one electrode, through the LUMO of the acceptor, and then to the other electrode when said electrodes are held at certain voltages, and result in rectification if the acceptor …

Carbon Dioxide Reduction Using Redox-Active Macrocyclic Catalysts, Dawson Kendall Buettner

Honors Theses

The current energy crisis experienced by society today is in desperate need of a solution. Through carbon dioxide (CO2) reduction, we can reduce the amount of greenhouse gas that is warming our planet as well as create a source of renewable energy. Significant challenges currently inhibit the reduction of CO2 to more desirable products. Current limitations can be addressed through the design and synthesis of more efficient catalysts that are selective, durable, and operate close to the target thermodynamic potential of CO2 reduction. In this work, three redox-active macrocyclic ligands have been synthesized and studied for the development of potential …

Time- And Ph- Dependent Proteolysis Of Engineered Proteins By Collagenase, Hunter Berry

Honors Theses

Pleiotropic effects from oral administration of anti-inflammatory drugs limit their effectiveness. The ultimate goal of this project is to develop a novel self-assembling protein-based hydrogel for in situ delivery of NSAIDs at the site of chronic inflammation. Since inflammation causes acidification and activation of collagenases in the inflamed tissue, we have designed the hydrogel to respond to both of these queues to effectively deliver drug at the site. Self-assembly of the protein hydrogel exploits the high affinity and specific interaction between the protein calmodulin (CaM) and its specific binding peptide, M13. The two components of the hydrogel, CCLP and PCLP …

Protein Templated Silver Nanoclusters, Greyson Keel

Honors Theses

Nanoclusters are smaller than their nanoparticle counterparts and have unique properties. Most research has been done on gold nanoclusters, but silver nanoclusters are said to be more robust. During the process of trying to create nanoclusters, several methods in the procedure were changed when gathering data: determining a successful silver concentration, working with the correct buffer, mixing gold and silver metals together, observing the effects of pH, and finding a good reducing agent. After experimenting with those changes, a successful protocol was adapted and modified from literature (Journal of Materials Chemistry, 2011, 21, 11205-11212) to produce the protein-templated Ag clusters. …

Assessing The Effects Of Antioxidants On Oxidative Stress In Triple-Negative Breast Cancer Cells Via Protein Carbonylation, Dalton Sheffield

Honors Theses

Breast cancer is a highly complex, heterogeneous disease, and potential effective treatment options are being continuously researched in order to provide a method of halting cancer growth and metastasis. One area in particular involves alleviating oxidative stress within cancer cells. Oxidative stress is generally defined as an imbalance between oxidant and antioxidant species in favor of the oxidants. Cancer cells use this oxidative stress to initiate carcinogenesis in cells through different mechanisms, and protein carbonylation is a primary biomarker used to quantify oxidative stress levels. Antioxidant compounds are those used to alleviate oxidative stress within cells. Here breast cancer cells …

Synthesis Of Oxygenated Boronic Acid Substituted A-Cyanostilbenes For Use As Antibacterial, Yewon Kim

Honors Theses

Stilbenes are naturally occurring compounds that have exhibited antibacterial activity, although the biological effect of various stilbenes differs for Gram-positive and Gram-negative strains of bacteria. In prior research, cyanostilbenes have shown slight antibacterial activity (Brownlee, et al. 1943). This project aims to explore whether hybrid oxygenated a-cyanostilbenes possessing a boronic acid pharmacophore exhibits significant antibacterial activity (Das et al. 2013). The biological activity against Staphylocococcus aureus (Gram-positive) and Escherichia coli (Gram-negative) was tested using the Kirby-Bauer text. No inhibition of E. coli growth was shown while S. aureus was partially inhibited.

Evaluating Mutagenicity Of Burned Arginine-Based Heterocyclic Amines And Anti-Mutagenicity Effect Of Chinese Medicinal Herbs, Rayford C. Alva

Honors Theses

From the unexpected finding that cooked grains and meat substitutes elicit a mutagenic response in Salmonella typhimurium TA98, our work has been aimed at deconstructing this finding via a survey of heated binary amino acid combinations, involving arginine, a plant-based amino acid. secondly, our work has looked towards sing phytochemical extracts from traditional Chinese medicinal herbs to inhibit the mutagenic activity of heterocyclic amines (main culprit for mutagenicity in meat). Two fractions from the burned products of arginine and phenylalanine (RF-HCA-06 and -07) were statistically significant inducers of mutagenesis; Scutellaria barbata and Oldenlandia diffusa, both separately and together, were statistically …

Investigating Phosphorylation Patterns And Their Effect On The Activity Of Transcription Factor Taabf1 In Imbibing Cereal Grains, Grace Uwase

Honors Theses

The wheat transcription factor TaABF1 plays an important role in hormone-mediated regulation of seed dormancy and germination of cereal grains. Evidence shows that TaABF1 activity is regulated by phosphorylation, and previous work in our lab showed that when serine residues in its conserved regions; S36, S37, S113, S115 were altered to phosphomimetic aspartate, the 4xD TaABF1 mutant had increased activity as a transcription factor. However, when only S113 was altered, TaABF1’s activity was greatly reduced. The work presented here explored whether the S36D/S37D/S115D mutant would have stronger activity than the 4xD mutant. Using the particle bombardment technique to introduce the …

Haloferax Volcanii For Carotenoid Production, Erika Smith

Honors Theses

Carotenoids are used as natural colorants and have been shown to have numerous health benefits, making these molecules highly desirable in the aquaculture, pharmaceutical, and nutraceutical markets. There is increasing consumer demand for the natural synthesis of carotenoids, but current methods are limited by the cost and difficulty of extraction from organisms. The halophilic archaeon Haloferax volcanii is amenable to extraction and has an endogenous carotenoid biosynthetic pathway that culminates in the accumulation of the carotenoid bacterioruberin; however, H. volcanii also synthesizes important precursors that can be converted into more highly-desired carotenoids, such as β-carotene and astaxanthin, in the presence …

Prep-Hplc Method Development To Isolate Potentially-Carcinogenic, Arginine-Based Heterocyclic Amines, Victoria S. Kim

Honors Theses

Heterocyclic amines (HCAs) are carcinogenic molecules generated from the reaction of creatin(in)e and amino acids at high cooking temperatures in meat. Previous research has shown that replacing creatine with arginine leads to new, uncharacterized HCA molecules. This research entails implementing and optimizing the preparative HPLC analysis of extracts from multiple burnings of arginine with phenylalanine. Isolated fractions from the prep-HPLC analysis were further analyzed using the Ames test to identify mutagenic compounds. Prep-HPLC provides quality control to the burning process along with isolation of larger quantities of materials for further characterization and molecular structure identification.

Characterization Of P43lgrn-3, Kelly G. Hill

Honors Theses

Alzheimer’s Disease (AD) is a progressive neurodegenerative disorder characterized by extensive memory loss and cognitive deficits, which occur due to severe neuronal loss. Two hallmark lesions, intracellular neurofibrillary tangles composed of hyperphosphorylated tau and extracellular neuritic plaques formed by the aggregation of amyloid-β (Aβ), are responsible for the progressive neuronal loss seen in AD brains. Neurotoxic Aβ aggregates are also known to cause inflammation within the brain. It has recently come to light that severe and acute inflammation, such as seen in traumatic brain injury (TBI), may also lead to AD-type dementia. This has raised the question whether some of …

The Preparation Of Synthetic Myod Mrna For Cellular Differentiation And Innate Immune Response Downstream Application, James D. Grenn

Honors Theses

The development of therapeutic immune responses from the manipulation of embryonic stem cells (ESCs) via induction of synthetic RNA with 5’ capped and 3’ poly(A)tailed ends would lead to development of stem cell therapy. A necessary step in attaining such a goal is to first produce an mRNA transcript from a plasmid containing the open reading frame (ORF) for a transcription factor for cellular activation.

In this research, the DNA plasmid pMD4 encoding MyoD was transcribed into synthetic mRNA. The plasmid was first amplified using Polymerase Chain Reaction (PCR), and analyzed using gel electrophoresis. The amplified template was purified via …

Altering The Structure Of Carboxysomal Carbonic Anhydrase Csosca To Determine The Necessity Of The N-Terminal Domain In Csosca Function, Dana L. Dillistone

Honors Theses

In this project, a DNA construct was designed and developed to remove the first fifty amino acids of the CsoSCA protein in the chemolithotrophic bacterium Halothiobacillus neapolitanus. The csoS3 gene codes for a carbonic anhydrase enzyme (CsoSCA) that is unique to a structure called a carboxysome. Carboxysomes are polyhedral microcompartments where carbon fixation is housed. The carbonic anhydrase is a shell-associated protein that improves the catalytic efficiency of ribulose-bisphosphate carboxylase/oxygenase (RuBisCO), the enzyme that catalyzes the fixation of carbon. By deleting the first fifty amino acids of the carbonic anhydrase, the necessity of the amino acids in carboxysome function was …

Elucidating The Interplay Between Sodium Selenite On The Tick Amblyomma Maculatum Selenoprotein Gene Expression, Afnan M. Beauti

Honors Theses

Selenium (Se) is an element recognized as an essential micronutrient in eukaryote organisms. Selenoproteins contain selenium as selenocysteine, the 21st amino acid. Selenium plays a role in cell growth and functioning. At low concentrations, it can induce growth and at high concentrations, it can cause a cell to stop growing and potentially have toxic effects on the cell and organism. When selenium levels are high, oxidative stress results by the production of reactive oxidative species. Selenoproteins, however, can aid the antioxidant response in the cell. Ticks are arthropods of interest, as they are one of few that contain many selenogenes, …

Generation Of Mutant Snap-23 To Arrest Mast Cell Degranulation At Trans-Snare Complex Formation, Suzette Wafford-Turner

Honors Theses

Regulated secretion of pro-inflammatory molecules (e.g, histamines, proteases) from mast cells plays critical roles in immunity, allergic reactions, cardiovascular disease and cancer. These molecules are stored in secretory granules inside the cell and are rapidly released into the extracellular environment when mast cells are activated. It is known that mast cell degranulation depends upon membrane anchored SNAREs (soluble N-ethylmaleidimide-sensitive factor attachment protein receptors) and accessory proteins that form the trans-SNARE complex, a 4 helical bundle central to exocytic fusion. There are three SNARE proteins that contribute to the 4-helical bundle during exocytosis; Syntaxin and VAMP proteins each provide one helix …

Molecular Mass Of L-Arginine-Based Potentially Carcinogenic Heterocyclic Amines, Irene S. Hwang

Honors Theses

Investigation of cancer-inducing molecules in cooked foods has led to the discovery of mutagenic heterocyclic amines (HCAs) in meat. The amino acids creatin(in)e and L-phenylalanine form the precursors for these HCAs. Recent research here at Andrews University have found similar mutagenic HCAs produced from plant-based proteins when L-arginine, rather than creatin(in)e, is substituted in high temperature reactions (simulated cooking) with L-phenylalanine. Our research focused on developing HPLC methods to isolate individual candidates that are then screened for mutagenicity via the Ames test. Mass spectroscopy methods were also developed to identfy the molecular structure of these lead mutagenic L-arginine-based HCAs.

Fluorescence Analysis Of Pamam Dendrimers, Ansel Nam

Honors Theses

Despite their lack of conjugation, polyamidoamine (PAMAM) dendrimers are intrinsically fluorescent, and this fluorescent is somewhat manipulable through altering the dendrimer's solvent. This level of fluorescence is dependent on a number of the dendrimer's qualities: the pH of the solvent, the mass percent concentration of the dendrimer in solvent, and the generation size of the dendrimer. In past studies, fluorescent intensity increased as generation size increased and pH decreased. Thus, this research project will attempt to replicate those results as well as further analyze the efficiency of fluorescence of PAMAM dendrimer in comparison to fluorescein.

Investigating Medicinally Important Portein-Protein And Protein-Ligand Interactions : A Computational Approach, Cooper Ashley Taylor

Honors Theses

Molecular dynamics (MD) simulations and computational chemistry allow for an atomistic understanding of protein-protein and protein-ligand binding motifs. Through the use of MD, medicinally relevant complexes can be examined in detail unattainable by experimental methods. Within this work, systems pertinent to both Alzheimer’s Disease and HIV-1 are probed and thoroughly sampled to help elucidate potential therapeutic pathways. We used molecular dynamics and free energy estimations to gauge the affinity for the binary and ternary complexes of KLC1, APP and JIP1, three proteins all believed to be involved in the propagation of Alzheimer’s Disease. Two areas of thought exist suggesting that …

Examining Interactions Between Opsins And Carotenoid Biosynthetic Proteins In Halophilic Archaea, Alexandru M. Plesa

Honors Theses

Organisms have evolved numerous specialized molecules for constantly responding to environmental changes. Examples of such molecules are the light-driven proton-pump rhodopsins, such as bacteriorhodopsin (BR) and cruxrhodopsin (cR), and the carotenoid pigments, such as retinal and bacterioruberin. In halophilic Archaea, retinal can covalently bind bacterioopsin (BO) and cruxopsin (CO) to form the corresponding protein complexes, and its biosynthesis is indirectly controlled by the activity of the lycopene elongase (Lye) enzyme, which converts lycopene, a retinal precursor, to a form of bacterioruberin. Interestingly, opsins were shown to inhibit the activity of Lye, thereby promoting retinal biosynthesis and indirectly regulating the apoprotein-cofactor …

Functional Significance Of Branch Points In Mirtrons, Britton A. Strickland

Honors Theses

MicroRNAs are a heterogeneous group of small regulatory RNAs generated by many pathways. Mirtrons (miR) are a class of microRNAs produced by splicing, and some mirtrons contain a 3’ tail located downstream from the self-complementary hairpin. During RNA splicing, a loop-like “lariat” intermediate structure is created when the 5’ end of the RNA is attached to an adenine called the branch point. The goal of this project is to uncover the contribution of branch point location to the processing of tailed mirtrons into functional gene regulators. This project approaches this issue from two directions. First, branch points were identified by …

Expression Of Glycine-Rich Proteins Found In Salivary Glands Of The Lone Star Tick (Amblyomma Americanum) Using A Mammalian Cell Line, Annabelle Clark

Honors Theses

Ticks play an important ecological role as well as a growing role in human health and veterinary care. Ticks are hosts to a plethora of microbial pathogens that can be transferred during feeding to cause tick-borne diseases in humans and many animals. Ticks may in large part owe the success of the transfer of these pathogens between hosts to their complex saliva. The saliva secreted upon a tick’s attachment to a host serves the following, among other, functions: anti-hemostasis of the blood pool, preventing an inflammatory response at the bite site, and serving as a natural anti-microbial substance. An important …

Development Of A [2]-Catenane Synthetic Method And A Student Beliefs Survey For A Hybrid Organometallics Course, Jourdan E. Lakes

Honors Theses

In this study, the value-added of a new upper-level chemistry course, CHEM 372-Organometallics, was defined using a Student Beliefs Survey that was answered by students in CHEM 372 and by faculty who teach upper-level chemistry courses at Coastal Carolina University. The laboratory portion of CHEM 372 focused on the synthesis of a [2]-catenane, which is a molecularly interlocked molecule (MIM). The intention was to give the CHEM 372 students a goal to work toward over the course of the semester instead of different, unrelated, experiments each week. Using this style of lab teaching, the students were introduced to graduate school-level …

Developing A Deletion Construct Of The Halothiobacillus Neapolitanus Csos1c Gene, Ellyn K. Dunbar

Honors Theses

The purpose of this research was to develop a deletion construct for the chemoautotrophic bacterium Halothiobacillus neapolitanus, which will be used to generate a mutant lacking a carboxysome shell protein gene. The carboxysome is the location of carbon dioxide fixation. The operon that encodes the carboxysome contains three genes for CsoS1 proteins, the major components of the carboxysome shell. The small CsoS1 proteins self-assemble into hexamers with small central pores. The hexamers arrange into the facets of the icosahedral carboxysome shell. The pores are believed to be involved in selective diffusion of materials necessary for carbon dioxide fixation across the …

Painless Hematophagy: The Functional Role Of Novel Tick Metalloproteases In Pain Suppression, Joseph W. Jelinski

Honors Theses

Ticks secrete a plethora of pharmacologically active molecules in their saliva while feeding. These allow the tick to feed upon a host over prolonged periods of time in an itch free and painless attachment. The exact mechanism of pain suppression by the tick has barely been investigated. In this study, two angiotensin converting enzymes (ACEs), members of the metalloprotease family, are identified as potentially responsible for the degradation of pro-inflammatory peptides. It is hypothesized that these tick ACEs block the function of bradykinin through degradation of the peptide, contributing to the tick’s ability to conduct a pain and itch-free host …

Using Intrinsic Properties Of Polyaniline To Sense Expression Of The Microrna Let-7, Jared N. Gloria

Honors Theses

MicroRNAs are approximately 22-nucleotide long RNA molecules that function through decay and translational repression of messenger RNA. The microRNA let-7 is found to play a role in maintaining the fate of differentiated cells in humans. Thus, expression level of this microRNA is a reliable biomarker of tumor cell phenotype. However, there are significant limitations in the current profiling techniques of microRNA. The current methods like northern blotting, microarrays, RT-PCR, or using locked nucleic acid (LNA) for in-situ hybridization are either laborious, semi-quantitative, or expensive. In this research we try to address this issue by developing a fast, specific, and inexpensive …

Effects Of Creatine, Leucine, And Ethanol On Glial Cell Line-Derived Neurotrophic Factor In C2c12 Skeletal Muscle Cells, Daniel Waters

Honors Theses

Glial Cell Line-Derived Neurotrophic Factor (GDNF) is a protein expressed throughout the mammalian nervous system that serves several protective functions. Originally discovered in the brain, where it supports the survival of dopaminergic neurons, GDNF has since been shown to be expressed in skeletal muscle and is vital for the maintenance of motor neurons. The relationship between muscle hypertrophy, and GDNF is not well understood. The purpose of this study was to examine the relationship between hypertrophy and GDNF by inducing hypertrophy in C2C12 skeletal muscle cells using leucine and creatine, inhibiting hypertrophy using ethanol and measuring GDNF content. As measured …