Biochemistry Commons^™

Understanding Dna Condensation By Low Generation (G0/G1) And Zwitterionic G4 Pamam Dendrimers, Min An

Theses and Dissertations--Chemistry

Cationic polymers have shown potential as gene delivery vectors due to their ability to condense DNA and protect it from cellular and restriction nucleases. Dendrimers are hyperbranched macromolecules with precisely defined molecular weights and highly symmetric branches stemming from a central core. The nanosize, tunable surface chemistries and ease of surface functionalization has made dendrimers an attractive alternative to conventional linear polymers for DNA delivery applications. The commercially available, cationic dendrimer poly(amidoamine) or PAMAM is the most widely studied dendrimer for use as a gene delivery vector. The aim of this dissertation is to provide an increased understanding of the …

The Development Of Colorimetric Assays To Determine The Identity And Frequency Of Specific Nucleobases In Dna Oligomers, Elizabeth Marie Thomas

Theses and Dissertations--Chemistry

Colorimetric methods combined with color-changing chemical probes are widely used as simple yet effective tools for identifying and quantifying a wide variety of molecules in solution. For nucleic acids (DNA and RNA), perhaps the most commonly used colorimetric probe is potassium permanganate, which can be used to identify single-stranded pyrimidines (thymine and cytosine) in polymers. Unfortunately, permanganate is not an effective probe for identifying purines (adenine and guanine), especially in the presence of the more reactive pyrimidines. Therefore, robust methods for discriminating between the purines remain elusive, thereby creating a barrier toward developing more complex colorimetric applications. In this dissertation, …

Assembly And Degradation Of A Trimeric Membrane Protein Acrb, Qian Chai

Theses and Dissertations--Chemistry

Multidrug efflux pumps are membrane proteins that actively transport foreign objects out of cells. The active efflux of these pumps is a critical self-defense mechanism that enables the survival of bacteria under hostile environments. Efflux pump AcrB is a member of the Resistance-Nodulation-Division (RND) super family. In E. coli, it associates with periplasmic protein AcrA and outer membrane channel TolC to extrude a variety of noxious compounds out of cell from both the cytoplasm and the periplasm. My dissertation research focused on two aspects of this multidrug efflux pump: the oligomerization process during the biogenesis of AcrB and its …

Reduction Of Oxidative Stress And Storage Lesions (Rcsl) In Red Blood Cells - Analysis Of Ascorbic Acid (Aa), N-Acetylcysteine Amide (Ad4), And Serotonin (5-Ht), Shanmuka Gadiraju

UROP Posters

Oxidative stress is a common occurrence in red blood cell (RBC) storage in blood banks throughout the world. Typically RBC units stored under routine standard protocol (stored in SAGM-CPD additive solution) can only be kept up to 42 days for transfusion usage before being discarded. I am studying the effects of Ascorbic Acid (AA), N-acetylcysteine amide (AD4), and Serotonin (5-HT) as additives in blood bank storage because I want to find out if these additives can reduce storage-induced oxidative stress on red blood cells (RBCs), in order to help my reader understand how potential blood storage additives can affect the …

The Characterization Of A Recombinant Virophage Integrase, Martin Christopher Chacon

Open Access Theses & Dissertations

Virophages are satellite-like dsDNA viruses that parasitize giant viruses of the family Mimiviridae. Mavirus is the second virophage discovered that associates with its host virus Cafeteria roenbergensis Virus (CroV). When co-infecting their common host cell Cafeteria roenbergensis, a marine zooplankton that is widely spread throughout the oceans, mavirus will inhibit CroV's replication. In addition, mavirus was shown to share high similarities to the Maverick/Polinton eukaryotic DNA transposons. A coding sequence in mavirus genome (MV02) reveals high homology to retroviral integrases such as those found in HIVs. The putative integrase MV02 is predicted to integrate mavirus DNA into the host genome. …

Development Of "Inside-Out" Pegylated Crosslinked Hemoglobin Polymers: Novel Hemoglobin-Based Oxygen Carriers (Hboc), Kyle Douglas Webster

Dissertations

The development of an effective blood substitute is urgent due to increasingly common blood shortages, the need to type-match donated blood, and communicable diseases (e.g. HIV) posing risks for blood transfusions around the world. There have been many attempts at creating hemoglobin-based oxygen carriers (HBOC) using a variety of techniques centered around the use of polyethylene glycol (PEG) conjugated to hemoglobin (Hb) tetramers. A novel method, “Inside-Out” PEGylation, has been developed by our lab to produce a polyethylene glycol crosslinked hemoglobin (PEG XL-Hb) polymer. This method utilizes a single PEG backbone that is surrounded by multiple proteins, instead of covering …

Attempted Identification Of The Calcium-Dependent Sodium Channel Gene In Paramecium Tetraurelia Using Rnai, Gwendolyn Kuzmishin

Senior Independent Study Theses

Ion channels play an important role in the swimming behavior of Paramecium tetraurelia. Electrophysiological experiments indicate that a calcium-dependent sodium channel exists in Paramecium, but a gene has not been identified for this channel. It is hypothesized that this channel evolved from a voltage-dependent sodium channel after a whole genome duplication event. In this paper, 13 candidate genes were identified from the Paramecium genome based on their similarity to a reference human voltage-dependent sodium channel. Bioinformatics analysis of the selectivity filter of these putative ion channel genes suggested that at least 8 of the candidate genes were sodium channels …

High Borate Glasses For The Controlled Release Of Therapeutic Metal Ions, Kathleen O'Connell

Theses

Within the biomaterial community significant effort has been directed towards engineering materials that induce precise host responses, which are tailored to specific applications. However, this has also seen an increase in the complexity of some biomaterials, which is being increasingly criticised within the literature, as it is attributed to hindering their clinical utility. In this context the release of therapeutic metal ions from glass-based biomaterials have been shown to promote hard tissue repair and regeneration through angiogenesis and osteogenesis processes. Within this thesis project two separate quaternary high borate glass systems were prepared containing the therapeutic metal ions strontium and …

Lipid-Protein Interactions Via Fluorescence Quenching In Small Unilamellar Vesicles, Talia Kordahi

Williams Honors College, Honors Research Projects

Studying peptide interactions with model membranes have aided in understanding protein-lipid interactions more clearly. In this report, fluorescent small unilamellar vesicles (SUVs) of a known composition were made. Two peptides, RND1 and MARCKS, were also fluorescently labeled and added to a solution of SUVs. The interactions between these were observed via fluorescence quenching, read out with a spectrofluorimeter. In addition, two environments of buffer were tested: 1X PBS and 0.1X PBS. After obtaining data, it was concluded that MARCKS quenched the SUVs more than RND1. This could be due to the presence of more lysine amino acids in MARCKS, which …

Investigation Of Dna Interaction With Bis-Cationic Imidazolium Salts, Kyle Daily 6440928

Williams Honors College, Honors Research Projects

Imidazolium salt compounds have shown promise in vitro against non-small cell lung cancer (NSCLC) lines, but the exact mechanism of activity these compounds is still unknown. Due to their planar aromatic structure, we hypothesized that our bis-cation imidazolium salt series could act through DNA intercalation similar to known intercalators ethidium bromide, acridine orange, and echinomycin. Here, we tested bis-cation imidazolium salts with linkers of 2, 4, 10, and 12 carbons for DNA intercalation via viscosity and fluorescent intercalator displacement (FID) assays. Despite some solubility issues that may have decreased results, we found that our butyl and dodecyl linked compounds had …

The Role Of Tgfβ1 And Ep Receptors In The Differentiation Of Normal And Diseased Lung Fibroblasts, Madison A. Hexter

Williams Honors College, Honors Research Projects

Fibroblasts, and their differentiation into myofibroblasts, are important in the pathology of several lung diseases including asthma and idiopathic pulmonary fibrosis (IPF). The differentiation process is dependent on several factors, such as soluble factors like transforming growth factor beta 1 (TGFβ1) and mechanical signals such as matrix stiffness. Additionally, the soluble arachidonic acid metabolite Prostaglandin E₂ (PGE₂) prevents TGFβ1 induced differentiation of fibroblasts to myofibroblasts, but the molecular mechanism is not completely understood¹⁵. Transient Receptor Potential Vanilloid 4 (TRPV4), a mechanosensitive ion channel, has previously been implicated in the differentiation of cardiac fibroblasts^12,13. …

Characterization Of A Phosphonate-Specific Cytidylyltransferase, Kissa Batul

Theses and Dissertations (Comprehensive)

Antibiotic resistance is a major global health concern that requires new therapeutic approaches. Furthermore, a lack of narrow spectrum antibiotics on the market produces unintended consequences with respect to changes in our microbial make up. Phosphonates are reduced versions of phosphates that possess a C-P bond which is more resistant to enzymatic and chemical degradation. The role of phosphonate containing macromolecules (e.g. cell surface polysaccharides) remains enigmatic, however their presence suggests that they may confer an advantage. The biosynthesis of phosphonate-containing macromolecules is unknown, but a pathway is proposed involving aLicC type cytidylyltransferase-catalyzed conjugation to a phosphonate followed by a …

A Biophysical Study Of The Ion Transport Mechanism In Uncoupling Protein 2 By Investigating The Role Of Lysine Residues In Its Matrix Network, Stephanie O. Uwumarenogie

Theses and Dissertations (Comprehensive)

ABSTRACT

Uncoupling protein 2 (UCP2) is one of five UCP homologues found in the inner mitochondrial membrane that transports protons from the intermembrane space to the mitochondrial matrix. In turn, the proton motive force is dissipated and less ATP is produced in the mitochondria. UCP2 is proposed to influence insulin secretion in type II diabetes, and decrease the amount of reactive oxygen species produced in the mitochondria, however the detailed mechanism of ion (proton and anions) transport in UCP2 and other UCP homologues are not fully understood. Sequence alignment analysis performed on proteins in the mitochondrial carrier family (MCF) including …

A Five Residue Insertion Between Codons 28 And 29 Of The Hiv-1 Protease Gene Reduces The Replicative Capacity Of The Virus, Cathy Mcleod

Wayne State University Theses

HIV-1 protease (PR) is a 99 amino acid protein responsible for cleavage of the viral polyprotein. We have identified a novel clinical isolate, MDR/28, which contains a five residue insertion between codons 28 and 29 of a multi-drug resistant (MDR) PR. This clinical isolate displays reduced viral replicative capacity compared to the wild-type. As opposed to drug-resistance mutations, studies on insertions remain largely underrepresented in the literature, and the consequences of such insertions are largely unknown. To understand the mechanism leading to reduced replicative capacity, three PR models were created and subjected to 40ns molecular dynamics simulations: MDR/28, wild type, …

Celecoxib Enhances Sorafenib/Sildenafil Lethality In Cancer Cells And Reverts Platinum Chemotherapy Resistance, Timothy A. Webb

Theses and Dissertations

The present studies sought to determine whether the lethality of the drug combination [sorafenib + sildenafil] could be enhanced by the anti-inflammatory agent celecoxib, using ovarian cancer and other tumor cell lines as models. Also, in a dose dependent fashion celecoxib enhanced [sorafenib + sildenafil] lethality in multiple ovarian cancer cell lines. In a dose dependent fashion celecoxib enhanced the ability of [sorafenib + sildenafil] to reduce expression of multiple chaperone proteins in parallel with lower levels of the drug efflux pumps ABCB1 and ABCG2. Over-expression of GRP78 and HSP27 maintained pump expression in the presence of drugs. Cell killing …

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.

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 …

Effects Of High Voltage Nanosecond Electric Pulses On Eukaryotic Cells (In Vitro): A Systematic Review, Tina Batista Napotink, Matej Reberšek, P. Thomas Vernier, Babara Mali, Damijan Miklavčič

Bioelectrics Publications

For this systematic review, 203 published reports on effects of electroporation using nanosecond high-voltage electric pulses (nsEP) on eukaryotic cells (human, animal, plant) in vitro were analyzed. A field synopsis summarizes current published data in the field with respect to publication year, cell types, exposure configuration, and pulse duration. Published data were analyzed for effects observed in eight main target areas (plasma membrane, intracellular, apoptosis, calcium level and distribution, survival, nucleus, mitochondria, stress) and an additional 107 detailed outcomes. We statistically analyzed effects of nsEP with respect to three pulse duration groups: A: 1–10 ns, B: 11–100 ns and C: …

Small Molecule Disruption Of Ros-Regulating Pathways In Human Carcinoma, Rebecca E. Mccall

College of Graduate Studies: Theses & Dissertations

Gold (I) coordinated N-heterocyclic carbenes containing appended redox cycling moieties were designed and analyzed for their ability to target the antioxidant network via multiple mechanisms in various human cancer cell models. Complexes containing either ferrocene or naphthoquinone redox cycling moieties were screened for inhibition of cell growth, inhibition of thioredoxin reductase (TrxR), and accentuation of exogenous ROS. The cell death pathway employed was determined by flow cytometry via detection of Annexin-V FITC. Furthermore, differential gene expression between treated cells and untreated cells revealed the induction of endoplasmic reticulum stress and unfolded protein response pathways.