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Investigation Of The In Vivo Activity Of Ribosome-Targeting Peptides And Aminoglycosides In Escherichia Coli, Nisansala Sarangi Thilakarathne Muthunayake

Wayne State University Dissertations

The development of short peptides that specifically bind to higher-order structures of ribosomal RNA is one promising way to address the problem of antibiotic resistance. However, the poor correlation between in vitro and in vivo activities of these peptides is one of the major questions in antibiotic peptide research. Therefore, one of the main objectives of this dissertation work was to utilize a plasmid-based system to in vivo express ribosome-targeting peptides and study their direct inhibitory effects on bacteria. A specific plasmid system was optimized to in vivo express oncocin, a prolin-rich antimicrobial peptide and its variants in bacteria. Our …

Functional Study Of Smyd2 Glutathionylation In Cardiomyocytes, Dhanushka Nalin Perera Munkanatta Godage

Wayne State University Dissertations

Reactive oxygen species (ROS) are important signaling molecules that contribute to the etiology of multiple muscle-related diseases, including cardiomyopathy and heart failure. There is emerging evidence that cellular stress can lead to destabilization of sarcomeres, the contractile unit of muscle. However, it is not completely understood how cellular stress or ROS induce structural destabilization of sarcomeres or myofibrils. Protein glutathionylation is one of the major protein cysteine oxidative modifications that play an important role in redox signaling and oxidative stress. In this report, we used a clickable glutathione approach in a cardiomyocyte cell line, and found that SET and MYND …

Biochemical And Cellular Studies Of Apobec3 Family Dna-Cytosine Deaminases, Sachini Umedi Siriwardena

Wayne State University Dissertations

The AID/APOBEC family of enzymes deaminate cytosines in single-stranded DNA to uracils leading to base substitutions and strand breaks. Members of APOBEC3 family in humans are induced by cytokines produced during the body's inflammatory response to infections and provide innate immunity against viruses. However, there is emerging consensus that these enzymes can cause mutations in the cellular genome depending on the physiological state of the cell and the phase of the cell cycle they are expressed. Since aberrant expression of APOBEC3B was recently identified as a possible source of cancer, we initiated a study to determine the maximally active catalytic …

Alternative Strategies To Inhibit Lysine Methyltransferases And Deubiquitinases In Human Cancers, Nicholas Spellmon

Wayne State University Dissertations

X-ray crystallography is the gold standard method for imagining macromolecules to atomic resolution. Three dimensional data is central to understanding the molecular mechanism how DNA, RNA and proteins function in biological events. Structural insights into these events provide a molecular window to visualize how biological molecules influence human health. Visualizing the architecture of these molecules set the stage for rational and selective drug design. The following dissertation utilizes biochemical and biophysical tools, including X-ray crystallography, to shed light on poorly understood mechanisms related to SMYD2 activity and regulation, USP10 architecture and function, and PDZ-RhoGEF dimerization. SMYD2 is one member of …

Investigation Of The Saccharomyces Cerevisiae Gpi Transamidase: Insights Into Its Activity And Subunit-Subunit Interactions, Travis Ness

Wayne State University Dissertations

Glycosylphosphatidylinositol (GPI) anchoring of proteins is a eukaryotic, posttranslational

modification catalyzed by GPI transamidase (GPI-T). The Saccharomyces

cerevisiae GPI-T is composed of five membrane-bound subunits: Gaa1, Gpi8, Gpi16,

Gpi17, and Gab1. Structural and functional studies have been hindered by the

complexity of this enzyme. Conditions to purify the Gpi8:Gaa1:Gpi16 GPI-T heterotrimer

from yeast have been reported, but an understanding of the subunit functions,

interactions, and stoichiometry remain unclear. Furthermore, a reliable, quantitative, in

vitro assay for this important post-translational modification has remained elusive for

nearly three decades.

Our laboratory has developed an in vitro peptide cleavage assay that correlates

changes …

Carbohydrate-Based Inducers Of Cellular Stress For Targeting Cancer Cell Metabolism, Fidelis Ndombera

Wayne State University Dissertations

ABSTRACT

CARBOHYDRATE-BASED INDUCERS OF CELLULAR STRESS FOR TARGETING CANCER CELL METABOLISM

by

FIDELIS TOLOYI NDOMBERA

May 2018

Advisor: Dr. Young-Hoon Ahn

Major: Chemistry (Biochemistry)

Degree: Doctor of Philosophy

Metabolic reprogramming and redox control of cancer cells is vital for their proliferation, but also provides selective strategies for treating cancer. Increased generation of reactive oxygen species (ROS) and an intricate control of redox status in cancer cells relative to normal cells provide a basis for designing ROS-inducing anticancer agents. In my work, I designed, synthesized and evaluated carbohydrate-based small molecules for ROS-generation, cytotoxicity and redox signaling and stress response. Our data …

Design, Synthesis, And Reactivity Of Homo- And Heterobimetallic Complexes Bridged By A Xanthene Linker, Thilini Samangi Hollingsworth

Wayne State University Dissertations

Cooperative reactivity of bimettalics can be is observed in many different areas of chemistry and have been increasingly investigated because of the advantageous reactivity when compared to the corresponding mononuclear systems. The focus of my dissertation is on (1) investigation of the homobimetallic cooperativity in lactide polymerization catalysis; (2) investigation of the heterobimetallic cooperativity in the biomimetic studies of Mo-Cu carbon monoxide dehydrogenase (CODH) enzyme in order to make a functional model of its active site.

Three new main group bis(alkoxide) complexes Mg(OR)2(THF)2, Zn(Cl)(μ2-OR)2Li(THF) and In(OR)2(μ2-Cl)2Li(THF)2 featuring bulky alkoxide [OCtBu2Ph] were synthesized serve as metal alkoxide precursors for bimetallic lactide …

Methionine Sulfoximine: A Novel Anti Inflammatory Agent, Tyler Peters

Wayne State University Dissertations

ABSTRACT

METHIONINE SULFOXIMINE: A NOVEL ANTI-INFLAMMATORY AGENT

by

TYLER J. PETERS

October 2018

Advisor: William Brusilow

Major: Biochemistry and Molecular Biology

Degree: Doctor of Philosophy

The glutamine synthetase inhibitor methionine sulfoximine (MSO), shown previously to prevent death caused by an inflammatory liver response in mice, was tested on in vitro production of cytokines by mouse peritoneal macrophages triggered with lipopolysaccharide (LPS). MSO significantly reduced the production of Interleukin 6 (IL-6) and Tumor Necrosis Factor Alpha (TNFα) at 4 and 6 hours after LPS-treatment. This reduction did not result from decreased transcription of IL-6 and TNFα genes, and therefore appeared to …