Biochemistry, Biophysics, and Structural Biology Commons^™

Structural Impacts Of Canonical And Non-Canonical Oligonucleotide Modifications, Deepak Shrestha

Wayne State University Dissertations

Nucleic acids, including DNA (deoxyribonucleic acid) and RNA (ribonucleic acids), are the fundamental building blocks of living organisms. The events that cause modification of DNA/RNA are of interest because they impact the nucleic acid function. Targeting DNA is important for treating diseases such as cancer. Cisplatin (cisPt) is a well-studied drug that targets DNA and blocks replication, but its use is limited by adverse side effects and cellular resistance. Prevoius research addressed some of these challenges through development of platinum analogues such as carboplatin and oxaliplatin. Amino acid-linked platinum analogues (AAPt) are the focus of this thesis work. AAPt complexes …

Mass Spectrometry Combined With Chemical Biology To Study Human Ailments, Eric Thomas Jacquerio Davis

Wayne State University Dissertations

Post-translational modifications (PTMs) are essential as chemical changes that regulate protein function, activity, stability, interactions, and localization after protein synthesis. PTMs, such as phosphorylation, acetylation, and ubiquitination, can activate or deactivate proteins, influence their interactions with other molecules, and determine their cellular location. This regulation is vital for numerous biological processes, such as cell cycle control, signal transduction, and gene expression. Abnormal PTMs are linked to various diseases in humans, including parasitic infection, blood disorders, cancers, and neurodegenerative diseases, making their study crucial for understanding disease mechanisms and developing targeted therapies. In the Pflum lab, we are interested in the …

Development And Application Of Enhanced Sampling Techniques For Investigating Protein Interactions And Drug Discovery, Timothy Hasse

Wayne State University Dissertations

Understanding the dynamics of protein–protein and protein–ligand interactions is critical for elucidating biological function and guiding drug discovery. However, many such processes involve rare events and high energy barriers that are difficult to capture with conventional molecular dynamics (MD). Enhanced sampling techniques extend the reach of MD, enabling access to biologically relevant transitions and thermodynamic properties. In the first project, Gaussian accelerated MD (GaMD) was used to study the MEIG1–PACRG complex, a key regulator of sperm flagellar assembly. Simulations of wildtype and mutant MEIG1 (W50A, Y68A) revealed mutation-specific disruptions to the binding interface and identified druggable pockets, particularly on PACRG. …

The Role Of Fruiting Bodies In Protecting A Community Of Myxococcus Xanthus Spores From The Environment, Dave Lall

Wayne State University Dissertations

Environmental microorganisms have evolved a variety of strategies to survive fluctuations in environmental conditions, including the production of biofilms and differentiation into spores. Myxococcus xanthus are ubiquitous soil bacteria that produce starvation-induced multicellular fruiting bodies filled with environmentally resistant spores (a specialized biofilm). Isolated spores have been shown to be more resistant than vegetative cells to heat, ultraviolet radiation, and desiccation. The evolutionary advantage of producing spores inside of fruiting bodies is not clear. Here, we examine a hypothesis that the fruiting body provides additional protection from environmental insults. We developed a high-throughput method to compare the recovery (outgrowth) of …

Microbial Prevalence And Antibiotic Resistance Associated With Urban Food Production Systems, Nirosha Ruwani Amarasekara

Wayne State University Dissertations

Despite the increasing popularity of urban agriculture and farmers’ markets, there is a lack of scientific data on microbial prevalence and antibiotic resistance associated with this unique food production system. The overall goal of this research is to understand antibiotic resistance and microbial prevalence in soil and fresh produce associated with urban agriculture. Specifically, we aim to investigate ARG in association with resistance genes to metals and other compounds in urban agricultural soil as well as antibiotic resistome and Listeria contamination in fresh produce distributed in urban communities.

In the initial phase of this research, soil samples were collected from …

Uracil Landscape Of Mouse B Cell Genome Undergoing Class-Switch Recombination, Fathima Rukshana Mohamad Ramshan

Wayne State University Dissertations

Activation-induced cytosine deaminase (AID) is required for both somatic hypermutation (SHM) and class switch recombination (CSR) within mammalian antibody genes. Uracils created by AID in the Ig loci are recognized and processed by base-excision and mismatch repair pathways leading to antibody diversification. This involves a hypermutation process restricted to the V(D)J segments of the immunoglobulin genes, SHM, and an error-prone end-joining process that causes isotype switching, CSR, but the molecular details of these processes have remained obscure for the past 20+ years. Most studies of SHM and CSR have used AID-promoted mutations as a proxy for the uracils, but their …

Design, Synthesis, And Evaluation Of Class Iia Histone Deacetylase (Hdac) Inhibitors, Lauren Nicole Kotsull

Wayne State University Dissertations

Histone deacetylase (HDAC) proteins are linked to disease states, including cancer, and have become important targets for therapeutic development. Many inhibitors have been developed to target HDAC proteins, including FDA-approved inhibitors Vorinostat (SAHA), Belinostat, Romidepsin, and Panobinostat. These inhibitors non-specifically influence most of the 11 metal-dependent HDAC isoforms, which might contribute to the side effects that patients experience during treatment. The lack of selectivity also diminishes the use of HDAC inhibitors as biomedical research tools. To address these drawbacks, the development of selective inhibitors has been heavily studied. Yet, reported inhibitors are predominantly selective for class I HDAC isoforms (HDACs …

Benzene Exposure In Reproductive Biology: A Comprehensive Analysis Of Placental Response And Molecular Mechanisms In Trophoblast Function, Anthony Maxwell

Wayne State University Dissertations

The increase in environmental challenges and exposure to pollutants like benzene poses pressing concerns for reproductive health. This dissertation investigates the impact of benzene exposure during gestation on placental function, a key determinant for fetal development and pregnancy outcomes. Our work establishes that benzene exposure during pregnancy induces maternal immune activation, leading to increased rates of fetal resorptions, compromised fetal growth, and abnormal placental development. Intriguingly, we identify a sexual dimorphic response in male and female placentas to benzene exposure, attributable to inherent differences between male and female placental biology. On a molecular level, benzene is metabolized into hydroquinone in …

Dual Mechanisms Contributing To Pyruvate Dehydrogenase Activity Deficiency In A Barth Syndrome Cell Model, Zhuqing Liang

Wayne State University Dissertations

Barth syndrome (BTHS) is a rare genetic disease that results from mutations in the TAFAZZIN gene, which encodes the cardiolipin (CL) remodeling enzyme tafazzin (Taz). The mechanisms linking perturbation of CL remodeling and the pathological features of BTHS are not understood. We have recently reported that intermediary metabolism is perturbed in BTHS, and activity of the metabolic gatekeeper enzyme pyruvate dehydrogenase (PDH) is deficient in BTHS models. The mechanism whereby PDH is regulated by Taz is unknown, and this knowledge gap represents an obstacle to the development of therapeutics to treat BTHS. Using an established C2C12 myoblast model of BTHS, …

Biological Adaptations Leading To Metastatic Potential In Ovarian Cancer, Hussein Chehade

Wayne State University Dissertations

Ovarian cancer induces most deaths from gynecological cancers. Patients succumb due to heavy metastatic tumor burden, which accounts for 90% of cancer related deaths and is characterized by the dissemination of malignant cells from primary tumor to secondary site(s), partaking in cancer progression. Ovarian cancer progression is an extremely demanding process that requires cancer cells to be able to survive anoikis conditions and be metabolically flexible to survive microenvironmental changes during transit to a secondary site. Mitochondrial Nuclear Retrograde Regulator 1 (MNRR1) is a bi-organellar protein primarily present in the mitochondria by which it can prevent apoptosis and/or enhance mitochondrial …

From Culture To Metagenomics: A Comprehensive Evaluation Of The Female Reproductive Tract Microbiome In Pregnancy, Jonathan Panzer

Wayne State University Dissertations

The advent of Next Generation Sequencing technologies prompted novel investigations of the microbiome. These revealed both increased diversity of known microbiomes such as those of the gut, oral cavity and vagina, but also bacterial DNA in tissues previously considered sterile such as the blood, liver, brain, and placenta. Thus, previous paradigms of sterility, based primarily on culture data, were called into question. However, interpretation of bacterial DNA signals from low-microbial biomass tissues is complex due to the strong potential for contamination and interference from the surrounding environment. Yet, many new methodologies are being developed to help isolate valid bacterial DNA …

Kinase-Catalyzed Labeling To Identify Kinase-Substrate Pairs Using Γ-Phosphate Modified Atp Analogs, Rachel Beltman

Wayne State University Dissertations

Post-translational modifications (PTMs) are responsible for a variety of cellular processes. One such PTM is protein phosphorylation, which is catalyzed by kinases. Kinase enzymes play important roles in cellular signaling pathways, but dysregulation of kinase-mediated events results in the formation of diseases, which make kinases favorable drug targets. To uncover the role kinases play in the development of diseases, kinase-mediated cellular events need to be better understood. The current gap in the field is the lack of tools available to identify the kinase that is responsible for specific phosphorylation events within the cell. To improve the gap in the field, …

The Importance Of Protein Context In Spinocerebellar Ataxia Type 3, Sean Luis Johnson

Wayne State University Dissertations

Spinocerebellar Ataxia Type 3 (SCA3) is a member of the family of polyglutamine (polyQ) neurodegenerative disorders that includes Huntington's Disease and several other SCAs. SCA3, the most common dominant ataxia in the world, is caused by polyQ tract expansion in the protein, ataxin-3. How SCA3 occurs and how to treat it remain unresolved issues. The primary culprit of toxicity in all polyQ diseases is the glutamine repeat: its abnormal expansion leads to neuronal dysfunction and death. With that said, there is indisputable evidence that the way polyQ-dependent toxicity presents—areas impacted, cellular processes perturbed—is predicated in large part on regions outside …

Study Of Zyomogen Granule Movement Along Actin Filaments Using A Single Beam Optical Trap, Justin James Raupp

Wayne State University Dissertations

Zymogen granules are enzymatic vesicles in the pancreas. The surface of these zymogen granules (ZGs) has several different kinds of myosin molecules, such as myosin 1c, 6, 5c, and 7b. These molecular motors may contribute to ZG transportation in cells. To understand the molecular motors involved in the vesicle trafficking, we observed the in vitro motility of purified ZGs from rat pancreas and examined the stepping behavior and force that is generated using a single beam optical trap. To be involved in trafficking, molecular motors have certain characteristics, a high duty ratio and the ability to move continuously along actin …

Extending Plasma Proteome Coverage To Enable Biomarker Discovery, Jordan Bruce Burton

Wayne State University Dissertations

Two features make plasma a valued source of health information: First, plasma contains secreted proteins from all tissues in the body and can, therefore, provide information about the health status of all tissues. Second, plasma is available in large quantity using a minimally invasive procedure that is well tolerated. The status of plasma as a valued source of health information is matched by the difficulty in extracting proteome information from the samples. Using state of the art instrumentation a standard analysis of plasma yields quantitative information on approximately 300 proteins. Extreme fractionation strategies coupled with increased mass spectrometry time extends …

Identification Of Glutathionylated Cysteines Regulating Cell Migration, Dhanushika Kukulage

Wayne State University Dissertations

Cell migration is vital in many physiological processes, such as wound repair and metastasis. Impaired cell migration in wound healing may result in chronic wounds, by which 6.7 million Americans are affected, and they suffer from bacterial infections, amputations, increased mortality, and depression. Reactive oxygen species (ROS) or hydrogen peroxide (H2O2) play an essential role as a second messenger in redox signaling. Evidence has been found that H2O2 takes part in regulating cell migration as well. A primary mechanism of ROS regulating redox signaling is oxidative protein modifications. Protein S-glutathionylation, one of the oxidative modifications, is the conjugation of glutathione …

Characterizing The Post-Translational Modifications Of The Pro-Oncogenic Type Ii Transmembrane Serine Protease Tmprss13, Carly Elizabeth Martin

Wayne State University Dissertations

TMPRSS13, a type II transmembrane serine protease discovered at the turn of the century, has recently been shown to be significantly overexpressed in both breast cancer (BCa) and colorectal cancer (CRC), and to mediate chemoresistance in cell lines from both cancer types. Furthermore, loss of TMPRSS13 in a genetic model of mouse mammary carcinoma significantly reduced tumor burden and growth rate, and increased overall tumor-free survival. Its location on the cell surface as well as its low expression in normal breast and colon make TMPRSS13 an attractive candidate as an oncogenic biomarker and therapeutic target in cancer. However, little is …

Deconstructing Brown Adipocyte Neogenesis In Brown And White Adipose Tissue, Rayanne Burl

Wayne State University Dissertations

Global incidence of Type 2 Diabetes (T2D) has reached epidemic proportions, and increasing evidence indicates that dysfunctional adipose tissue is an important contributor to the pathogenesis of T2D. Expanding brown adipocyte (BA) populations within adipose tissues through adrenergic activation improves energy balance and insulin sensitivity. In order to exploit this remodeling of adipose tissue for therapeutic benefit, we need to understand the mechanisms by which adrenergic signaling expand populations of BAs in vivo. These studies utilized single-cell RNA-sequencing and transgenic mouse models, in combination with single-molecule fluorescence in situ hybridization (smFISH) and immunoistochemical analysis, to study BA neogenesis in vivo. …

Substrate Profiling Of The Epigenetic Erasers Hdac1 And Lsd1, Herath Mudiyansela Gedara Kavinda Eranga Herath

Wayne State University Dissertations

Regulators of chromatin structure have emerged as a key driver of transcriptional responses inside the cell. Two such groups of regulators, histone writers and erasers; the proteins, that add or remove histone post translational modifications (PTMs), have become the central players in chromatin structure. Thus, the aberrant expression of writers and erasures is a hallmark in human diseases. For example, overexpression of the erasures histone deacetylase1 (HDAC1) and lysine specific demethylase1 (LSD1) had been reported in many cancers. Currently, HDAC inhibitors have been used successfully for cancer treatment and several inhibitors targeting LSD1 are in clinical trial. To date, apart …

Developing Inhibitors Of Uchl5 Deubiquitinase In The Proteasome, Harshani Sewvandi Gurusingha Arachchige

Wayne State University Dissertations

Ubiquitin proteasomal system (UPS) plays a vital role in maintaining protein homeostasis by eliminating misfolded and damaged proteins in a eukaryotic cell. Target proteins to be degraded are modified by poly-ubiquitination, which leads to degradation by 26S proteasome. Before entering the 20S catalytic subunit, the 19S regulatory particle is responsible for binding, unfolding, and deubiquitinating the target protein. Based on the nature of the polyubiquitin tag, removal of the ubiquitin is performed by the deubiquitinases (DUBs) associated with the proteasome.Ubiquitin carboxyl-terminal hydrolase isozyme L5 (UCHL5) is one of the three DUBs in the proteasome. UCHL5 regulates many cellular functions and …

An In Vivo Inducible Expression System To Determine Antibacterial Activity Of Peptides, Rabiul Islam

Wayne State University Dissertations

The threat of bacterial resistance throughout the world has created tremendous challenges to clinicians. Some bacterial species have acquired resistance to not only single antibiotics, but also to multiple compounds, which is called multidrug resistance. Since the early discovery of resistance to penicillin, scientists have been developing new drugs to combat antibiotic resistance. In some cases, it took less than a decade to develop resistance to a new antibiotic. The World Health Organization (WHO) reported several deadly multi-drug-resistant bacteria, some of which cause life-threating illnesses. Each year more than 35,000 people in the United States die from antibiotic-resistant bacterial infections. …

Global Coordination Between Gene Expression Processes In C. Crescentus, James Raymond Aretakis

Wayne State University Dissertations

Gene expression is an essential process of all organisms which occurs in two steps, mRNA transcription, and translation and which is shut off by mRNA decay. For a bacterium to grow and divide, these steps need to be tuned to optimize the synthesis rates of thousands of proteins from their genes. Genome-wide experiments were used to determine the absolute transcription rates, mRNA degradation rates, and translation rates on a gene by gene basis in the model bacterium Caulobacter crescentus. This not only provides a system biology view of the organism’s gene expression resource allocation, but also provides a chance to …

Targeted Combination Therapy Of Triple-Negative Breast Cancer, Ketki Bhise

Wayne State University Dissertations

TARGETED COMBINATION THERAPY OF TRIPLE-NEGATIVE BREAST CANCERby KETKI BHISE May 2021 Advisor: Dr. Arun Iyer Major: Pharmaceutical Sciences Degree: Doctor of Philosophy Triple Negative Breast Cancer (TNBC) accounts for 10-20% of the total breast carcinoma cases. There is no FDA-approved targeted therapy for TNBC due to lack estrogen, progesterone and HER-2. We have identified the role of a hypoxia biomarker, carbonic anhydrase IX (CAIX) in proliferation and metastasis of TNBC. Based on this observation, we have developed CAIX-targeted Doxorubicin (Dox) prodrug, abbreviated as DoxAtz. To improve the delivery of DoxAtz to the tumor, we developed long circulating liposomes (LipoDoxAtz) and …

Mnrr1: Understanding The Role Of A Novel Mitochondrial-Nuclear Regulator, Stephanie L. Gladyck

Wayne State University Dissertations

Mitochondria are complex organelles that generate most of the energy required to sustain life and function in metabolic and signaling pathways required to maintain cellular homeostasis. MNRR1 (mitochondrial nuclear retrograde regulator 1 or CHCHD2) is a small, bi-organellar twin CX9C protein that is emerging as an important regulator of mitochondrial function, apoptosis, and cellular stress by participating in mitochondrial-nuclear crosstalk. Our lab has previously shown that in the mitochondria, MNRR1 regulates complex IV (Cytochrome c oxidase or COX) and is able to finetune the oxidase function through phosphorylation status. We have also shown that during stress, mitochondrial MNRR1 levels deplete, …

Development And Application Of Chemical Tools To Identify Kinase-Substrate Interactions, Aparni Kithulgoda Gamage

Wayne State University Dissertations

Post translational modifications regulate a variety of biological processes inside the cell.Protein phosphorylation is one such PTM modification catalyzed by protein kinases, which aid to transfer a signal from one place to another inside the cell. However, irregularities in kinase-mediated signaling are often implicated in many diseases, making kinases effective drug targets. To understand kinase-related disease formation and to discover drugs to treat these diseases, it is crucial to have a clear understanding on kinase-mediated cell signaling networks. A current gap in the kinase biology field is a lack of tools to identify which kinase phosphorylates which protein substrate inside …

Variations On A Theme: Intricacies Of Unanchored Poly-Ubiquitin Signaling And Toxicity, Jessica Renee Blount-Pacheco

Wayne State University Dissertations

Ubiquitin is an 8.5 kDa post-translational modifier involved in essentially all eukaryotic cellular processes. Through a process called ubiquitination, ubiquitinating enzymes chemically attach ubiquitin to substrate proteins to control their fates, resulting in anything from their recruitment into signaling pathways to their proteasomal degradation, with a plethora of possibilities in between. Ubiquitin molecules can also be attached to one another, resulting in poly-ubiquitin chains with various effects depending on the number of ubiquitin molecules and the specific amino acid residues used to link them together. While most poly-ubiquitin in the cell exists as conjugated species, there are also untethered poly-ubiquitin …

Use Of Alkoxyamines To Quantify And Map Uracils And To Kill B Cell Cancers, Madusha Lakshani Watuthanthrige Perera

Wayne State University Dissertations

Majority of B-cell lymphoma and leukemia originates in germinal centers and over express AID resulting high levels of uracils and eventually AP sites. Treating cells with a small alkoxyamine AA3 with a terminal alkyne group specifically killed B cell lymphoma cell lines without killing normal human B cells and non-hematological cancers. To study the cytotoxicity of AA3, I designed and synthesized a series of AA3 analogs with and without the alkyne group. Using cytotoxicity assays I demonstrated that the alkyne functionality plays a major role in AA3 cytotoxicity in B-cell cancers and further showed that the effectiveness is modulated by …

Computational Analysis Of Oxidative Stress In Endothelial Dysfunction: Insights On The Role Of Tetrahydrobiopterin, Ascorbate And Glutathione, Sheetal Kedar Panday

Wayne State University Dissertations

Oxidative stress and endothelial dysfunction are reported in the cardiovascular and neurovascular diseases. Oxidative stress is caused due to an increase in the generation of reactive oxygen (ROS) and nitrogen species (RNS) and incapacity of antioxidant systems to eliminate ROS and RNS. Endothelial dysfunction is characterized by a reduction in nitric oxide (NO) bioavailability. NO is constitutively produced by enzyme endothelial nitric oxide synthase (eNOS). A reduction in tetrahydrobiopterin (BH4), which is an essential cofactor of eNOS, can lead to eNOS uncoupling. There is complex interplay between the ROS/RNS and antioxidant system underlying pathophysiologies of vascular diseases, however our quantitative …

Timing And Duration Of Folate Restriction Differentially Impacts Colon Carcinogenesis., Ali M. Fardous

Wayne State University Dissertations

Colorectal cancer (CRC) constitutes a major burden on the healthcare system as the second most commonly diagnosed cancer in the developed world. Dietary folate is considered an important modulator of colorectal cancer. Folate restriction has been implicated in increasing CRC incidence by disrupting nucleotide synthesis, Impacting DNA methylation and inducing genetic instability. Our research shows that the timing and duration of dietary folate restriction can differentially impact Colorectal cancer initiation. Acclimating mice to folate restriction for 8 weeks results in a reduced number of preneoplastic lesions compared to mice placed of folate restriction for 1 week prior to initiating the …

Single-Lipid Sorting And Dynamics At Nanoscale Membrane Curvatures: The Effects Of Fluorescence Labeling, Composition, Phase, And Temperature, Xinxin Woodward

Wayne State University Dissertations

Nanoscale membrane curvature on cell plasma membrane assists in the spatial organization and domain formation that are critical for life of eukaryotic cells. Lipids and proteins can sense, be sorted by, and generate both functional domains and membrane curvature. Reveal the relationship between membrane curvature, phase separation, and single-molecule behavior is a key to understanding fundamental processes, such as phagocytosis initiation, cell signaling, and membrane budding. Single lipid dynamic and sorting on engineered membrane curvature is studied to understand the effects of fluorescence labeling, composition, phase separation, and temperature. Single particle tracking was used to find radial averaged diffusion at …