Medicine and Health Sciences Commons^™

Applied Molecular Dynamics: From Targeting Viral Helicases, To Understanding The Interactions Of Cucurbituril Complexes In Ionic Solutions, Bryan Raubenolt

University of New Orleans Theses and Dissertations

Molecular Dynamics simulations are a highly useful tool in helping understand the fundamental interactions present in a variety of chemical systems. The work discussed here illustrates it’s use in determining the conformational dynamics of the Zika and SARS-Cov-2 helicase in a physiological environment, largely in an effort to discover inhibitors capable of rendering the protein inert. Additionally, we show how it can be used to understand paradoxical trends in the anion-induced precipitation of Cucurbituril cavitands.

Viral helicases are motor proteins tasked with unwinding the viral dsRNA, a crucial step in preparing the strand to be translatable by host cells. By …

Assessment Of The Use Of Low Molecular Weight Diblock Copolymers For The Formation Of Stable, Tunable Droplet Interface Bilayers, Joseph Tawfik

Masters Theses

This thesis presents the use of diblock copolymers, poly(butadiene)-b-poly(ethylene oxide) (PB_m PEO_n) and poly(isoprene)-b-poly(ethylene oxide) (PI_mPEO_n), as amphiphilic molecular building blocks for the formation of synthetic polymer bilayer membranes using the droplet interface bilayer (DIB) technique. The DIB technique makes use of the self-assembly of amphiphilic macromolecules along oil-water droplet interfaces that can then be physically connected for the construction of liquid supported macromolecular bilayers at the droplet interface. These bilayer membranes are capable of hosting both naturally occurring and synthetic protein channels. This technique has been used to form synthetic bilayer membranes …

Deciphering The Ck2-Dependent Phosphoproteome And Its Integration With Regulatory Ptm Networks, Teresa Nunez De Villavicencio Diaz

Electronic Thesis and Dissertation Repository

Protein functions are regulated by the post-translational addition of covalent modifications on certain amino acids. Depending on their distance within the 3-dimensional structure, addition/removal of individual post translational modifications (PTMs) can be impacted by others. This PTM interplay constitutes an essential regulatory mechanism that interconnects the molecular networks in the cell. Protein CK2, a clinically relevant acidophilic Ser/Thr kinase, may be responsible for 10-20% of the human phosphoproteome. Such estimates agree with the number of known substrates, which continues to expand. Furthermore, the demonstration that CK2 participates in hierarchical phosphorylation and has similar sequence determinants to caspases suggest extensive PTM …

Cancer-Targeting Immunostimulatory Peptides As An Immunotherapeutic Approach To Cancer, Rachel Montel

Seton Hall University Dissertations and Theses (ETDs)

This dissertation reports the synthesis and biological applications of bifunctional trimeric peptides with B7H6-derived NKp30 binding motifs that serve to activate an immunocytotoxic response in natural killer cells and a GRP78-binding motif that can target tumors that express surface GRP78. In this manner the cancer-targeting immunostimulatory peptides are anticipated to directly bind and activate effector NK92-MI cells while also recognizing and binding to target A549 tumor cells to facilitate NK cell-dependent immunocytotoxicity of the targeted tumors. The NKp30 binding peptide motifs are derived from the tumor associated B7H6 antigen that is often downregulated or shed from the surface of tumors …

Directed Evolution Of Macrocyclic Peptides For Inhibition Of Autophagy, Joshua Gray

Dissertations & Theses (Open Access)

In recent decades it has become increasingly clear that induction of autophagy plays an important role in the development of treatment resistance and dormancy in many cancer types. Chloroquine (CQ) and hydroxychloroquine (HCQ), two autophagy inhibitors in clinical trials, suffer from poor pharmacokinetics and high toxicity at therapeutic dosages. This has prompted intense interest in the development of targeted autophagy inhibitors to re-sensitize disease to treatment with minimal impact on normal tissue. We utilized Scanning Unnatural Protease Resistant (SUPR) mRNA display to develop macrocyclic peptides targeting the autophagy protein LC3. The resulting peptides bound LC3A and LC3B—two essential components of …

Structural Analysis Of Protein Therapeutics Using Covalent Labeling – Mass Spectrometry, Patanachai Limpikirati

Doctoral Dissertations

Using mass spectrometry (MS) to obtain information about a higher order structure of protein requires that a protein’s structural properties are encoded into the mass of that protein. Covalent labeling (CL) with reagents that can irreversibly modify solvent accessible amino acid side chains is an effective way to encode structural information into the mass of a protein, as this information can be read-out in a straightforward manner using standard MS-based proteomics techniques. The differential reactivity of proteins under two or more conditions can be used to distinguish protein topologies, conformations, and/or binding sites. CL-MS methods have been effectively used for …

Designing Peptides To Bind Kappa B Dna And Mimic Nf-Kappa B Protein Complexes, Nicholas A. Markowich

Honors College Theses

Transcription factors are important proteins that regulate gene expression and protein synthesis. Transcription factors can either boost the gene’s transcription rate by helping RNA polymerase activate transcription or restrict it by interfering with RNA polymerase, thereby repressing transcription. Nuclear factor-kappa-B (NF-κB) transcription factors are a family of proteins that control the synthesis of proteins involved in many cellular processes such as inflammatory and immune responses, cell growth, and apoptosis. However, the overexpression and activation of these transcription factors is linked to deadly conditions such as cancer and neurodegenerative diseases which currently have few safe cures. The goal of this research …

Peptoid And Antibody-Based Gfp Sensors, Solomon Isu

Graduate Theses and Dissertations

In this work, we have made and characterized a pair of immunobiosensors for detecting the green fluorescent protein (GFP) in an aqueous matrix. An anti-GFP antibody-based biosensor was assembled to detect GFP, while a novel peptoid (N-substituted oligomers of glycine designated as IOS-1) biosensor was also assembled for GFP detection. A quartz crystal microbalance (QCM) gold sensor was used as the supporting substrate for self-assembly of the immunobiosensors. Gravimetric measurements of the QCM gold sensor during immunobiosensor construction and operation were available in real-time using a QCM instrument. X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and Fluorescence microscopy were used …

The Effects Watermelon Juice On Post Prandial Vascular Endothelial Function And Blood Flow During Hyperglycemia, Cullen M. Vincellette

LSU Master's Theses

Impaired endothelial function and microvascular dysfunction are frequently observed in individuals with cardiovascular risk factors such as obesity, insulin resistance, and type 2 diabetes. Reduced nitric oxide (NO) bioavailability is considered to be central to the development of these risk factors. NO can be generated via enzymatic reaction via NO synthase which requires the amino acid arginine. Evidence suggests that the amino acid citrulline is more effective at increasing circulating arginine levels than arginine supplementation alone. The purpose of this pilot study is to determine the potential for citrulline-rich watermelon juice (WMJ) to attenuate the reduction in postprandial endothelial function …

Network Approaches To Elucidate The Determinants Of Protein Topology And Stability, Zeinab Haratipour

Chemistry & Biochemistry Theses & Dissertations

Predicting three-dimensional structures of proteins from sequence information alone, remains one of the most profoundly challenging and intensely studied problems in basic science. It has uniquely garnered the interdisciplinary efforts of biologists, biochemists, computer scientists, mathematicians and physicists. The advancement of computational methods to study fundamental features of proteins also enables insights that are either difficult to explore experimentally or complimentary to further interpret experimental data. In the present research and through the combined development and application of molecular dynamics and network science approaches we aimed to elucidate the role of geographically important amino acids and evolutionarily conserved long-range interactions …

Analysis Of Oxidatively Damaged Proteins By Mass Spectrometry, Vincent Saullo

Electronic Thesis and Dissertation Repository

As humans age, exposure to oxidative stress may induce protein degradation or aggregation; both resulting in loss of protein function. Protein oxidative damage remains a dominant pathology in many common ailments. To combat these pathologies, scientists must understand the nature of oxidative modifications and their effects on protein structure and dynamics. This work employs a range of mass spectrometry (MS) methods to characterize and analyze the effects of oxidative damage on the model protein myoglobin (Mb). Mb was oxidized using tert-butyl hydroperoxide, and the resulting modifications were characterized by top-down and bottom-up MS workflows. Hydrogen/deuterium exchange MS indicated elevated structural …

Elucidating Molecular Function Of Mithramycin And Analogues For The Treatment Of Ews-Ets Expressing Cancers, Reiya Hayden

Theses and Dissertations--Pharmacy

Introduction: Chromosomal translocations are common in cancer. In many cancers such as prostate cancer, leukemia and Ewing sarcoma, chromosomal translocations are the main driver of malignancy. Ewing sarcoma is a cancer diagnosed mostly in children and adolescents that has very grim outcomes for patients with metastasis and recurrent disease. Malignancy in Ewing sarcoma is due to EWS-FLI1, an aberrant transcription factor that is the result of a chromosomal translocation. EWS-FLI1 is the main driver of oncogenesis in Ewing sarcoma and has been the target of many drugs developed to treat the disease. Mithramycin (MTM) was identified as a potent inhibitor …

Determining The Antibacterial Activity And Mode Of Action Of Tirandamycin, Hailey Bouchard

CMC Senior Theses

Tirandamycin is a small molecule natural product that has been isolated from various species of marine and terrestrial Streptomyces. The natural product has shown antibacterial activity against an array of Gram-positive and Gram-negative bacteria, showing promise as a pharmaceutical drug. Tirandamycin has 14 known derivatives, many of which have been created synthetically. Some of its derivatives are particularly potent against the high-risk bacteria vancomycin-resistant Enterococcus faecium, Staphylococcus aureus, Streptococcus agalactiae, Streptococcus pneumoniae and Escherichia coli. However, the antibacterial potency of these derivatives has not been tested systematically leading to the possibility of discovering more potent …

Ethanol Sustains Phosphorylated Tau Protein Immunofluorescence In The Cultured Neonatal Rat Hippocampus: Implications For Fetal Alcohol Spectrum Disorders, Caleb Seth Bailey

Theses and Dissertations--Psychology

Fetal Alcohol Spectrum Disorders (FASDs) are comprised of developmental, behavioral, and cognitive abnormalities caused by prenatal alcohol exposure, affecting an estimated 2%-5% of childrenand costing up to $4 billion annually in the United States alone. Although some behavioral therapies can help, the biochemical mechanisms that underpin FASDs need further elucidation for development of more efficacious therapeutics. The tau protein modulates cytoskeletal structure in neurons, and thereby plays an integral role in proper development and function of the central nervous system, but its function is altered by its phosphorylation state, such that increased phosphorylation reduces tau protein function. The tau protein …