Biochemistry, Biophysics, and Structural Biology Commons^™

Synthesis And Evaluation Of Azetidinone Analogues Of Combretastatin A-4 As Tubulin Targeting Agents, Niamh O'Boyle, Miriam Carr, Lisa M. Greene, Orla Bergin, Seema M. Nathwani, Thomas Mccabe, David G. Lloyd, Daniela M. Zisterer, Mary J. Meegan

Articles

The synthesis and antiproliferative activity of a new series of rigid analogues of combretastatin A-4 are described which contain the 1,4-diaryl-2-azetidinone (β-lactam) ring system in place of the usual ethylene bridge present in the natural combretastatin stilbene products. These novel compounds are also substituted at position 3 of the β-lactam ring with an aryl ring. A number of analogues showed potent nanomolar activity in human MCF-7 and MDA-MB-231 breast cancer cell lines, displayed in vitro inhibition of tubulin polymerization and did not cause significant cytotoxicity in normal murine breast epithelial cells. 4-(4-Methoxyaryl)-substituted compound 32, 4-(3-hydroxy-4-methoxyaryl)-substituted compounds 35 and 41 and …

Electric Pulses To Prepare Feeder Cells For Sustaining And Culturing Of Undifferentiated Embryonic Stem Cells, Lauren M. Browning, Tao Huang, Xiao-Hong Nancy Xu

Chemistry & Biochemistry Faculty Publications

Current challenges in embryonic-stem-cell (ESC) research include inability of sustaining and culturing of undifferentiated ESCs over time. Growth-arrested feeder cells are essential to the culture and sustaining of undifferentiated ESCs, and they are currently prepared using gammaradiation and chemical inactivation. Both techniques have severe limitations. In this study, we developed a new, simple and effective technique (pulsed-electric-fields, PEFs) to produce viable growth-arrested cells (RTS34st) and used them as high-quality feeder cells to culture and sustain undifferentiated zebrafish ESCs over time. The cells were exposed to 25 sequential 10- nanosecond-electric-pulses (10nsEPs) of 25, 40 and 150 kV/cm with 1s pulse interval, …

Chloroquine Susceptibility And Reversibility In A Plasmodium Falciparum Genetic Cross, Jigar J. Patel, Drew Thacker, John C. Tan, Perri Pleeter, Lisa Checkley, Joseph M. Gonzales, Bingbing Deng, Paul D. Roepe, Roland A. Cooper, Michael T. Ferdig

Biological Sciences Faculty Publications

Mutations in the Plasmodium falciparum chloroquine (CQ) resistance transporter (PfCRT) are major determinants of verapamil (VP)-reversible CQ resistance (CQR). In the presence of mutant PfCRT, additional genes contribute to the wide range of CQ susceptibilities observed. It is not known if these genes influence mechanisms of chemosensitization by CQR reversal agents. Using quantitative trait locus (QTL) mapping of progeny clones from the HB3 x Dd2 cross, we show that the P. falciparum multidrug resistance gene 1 (pfmdr1) interacts with the South-East Asia-derived mutant pfcrt haplotype to modulate CQR levels. A novel chromosome 7 locus is predicted to contribute …

Methionine-R-Sulfoxide Reductases And Biological Importance Of Free Methionine Sulfoxide Reduction, Byung Cheon Lee

Department of Biochemistry: Dissertations, Theses, and Student Research

We identified and functionally characterized yeast fRMsr homolog which showed specificity for reduction of free Met-R-SO and contributed to oxidative stress resistance of yeast cells. We further identified three conserved Cys which participate in catalysis through disulfide exchange. Evolutionary analyses revealed that the occurrence of fRMSr is restricted to unicellular organisms. We further found that mammalian MsrA can reduce free Met-S-SO, whereas MsrBs do not reduce free Met-R-SO. Consistent with these findings and the lack of fRMsr, mammalian cells could not grow in media that replaced Met with Met-R-SO. However, they grew in the presence of free Met-S-SO, which was …

Evaluating The Role Of Evolutionarily Conserved Regions Of Ledgf/P75 In Hiv-1 Infection, Jose Adrian Garcia

Open Access Theses & Dissertations

LEDGF/p75 is an important cellular co-factor for lentiviral integration. LEDGF/p75-deficient cells are markedly resistant to HIV-1 infection and re-expression of the wild type protein rescues infectivity. Although the molecular mechanism of LEDGF/p75 in HIV-1 integration is not yet known, this co-factor activity requires the interaction of LEDGF/p75 with both the host chromatin and viral integrase. In order to evaluate the involvement of other LEDGF/p75 regions in HIV-1 infection we constructed a panel of deletion mutants targeting clusters of charged residues that are evolutionarily conserved and predicted to be post-translationally modified. These mutants were evaluated for their ability to rescue HIV-1 …

Ganglioside-Cytokine Interaction In The Induction Of Primary Brain Cell Death, John Charles Gorbet

Open Access Theses & Dissertations

Gangliosides have been implicated in multiple pathologies affecting the central nervous system (CNS) and recent research has implicated them in playing an active role in the pathogenesis of multiple sclerosis. Empirical studies and theoretical considerations have suggested the possibility of interactions between gangliosides, like GD3, and pro-inflammatory cytokines present in the nervous system. This study sought to investigate the possibility that either individual gangliosides acting alone or complexed with other species interact with the known immune response factor TNF&alpha to initiate or facilitate cell death in the CNS. I examined the cellular viability and gene expression in primary brain cell …

Computer Aided Drug Design Methods & Quantitative Structure-Activity/Property Relationships, Suman Sirimulla

Open Access Theses & Dissertations

The first part of dissertation consists of development of a QSAR model for 229 mutagenic aromatic amines and a QSPR model of partial molar volumes of amino acids. A common procedure for QSAR analysis consist of data selection (generally sets of homologous series of compounds and their corresponding biological activities), tabulation of trial physicochemical or molecular structural descriptors, followed by a multilinear statistical analysis to derive a statistically valid QSAR correlation of the activity data making use of a subset of the trial descriptors. A final important step is cross-validation to assess the putative predictive (rather than just correlative) capabilities …

Effects Of The Loss Of Multidrug Resistance Associated Protein 1 On Steroid Homeostasis, Dendritic Cell Function And Compensatory Mechanisms, Jeffrey Charles Sivils

Open Access Theses & Dissertations

The ATP-binding cassette (ABC) superfamily of membrane transporters use energy derived from ATP to eliminate a variety of exogenous and endogenous compounds from cells including anti cancer and anti viral drugs, metals steroids, bilirubin, cAMP, cGMP, leukotrienes , prostaglandins. The multi drug resistance associated protein family (MRP/ABBC) has been acknowledged as a major player involved in multi drug resistance (MDR), in which cancers stop responding a wide array of structurally and functionally unrelated chemotherapy drugs. Cancer is the second leading cause of death in adults in the United States. Although there have been great strides made the treatment of cancers …

Phosphorylation Of The Glycine Transporter 1, Javier Vargas Medrano

Open Access Theses & Dissertations

The extracellular levels of the neurotransmitter glycine in the brain are tightly regulated by the high-affinity glycine transporter 1 (GlyT1) and the clearance of glycine depends on its rate of transport and the levels of cell surface GlyT1. Over the past years, it has been shown that PKC activation diminishes the activity and promoted phosphorylation of several neurotransmitter transporters including the dopamine, serotonin and norepinephrine transporters however, its role is unknown for the glycine transporter. To get insights into the role of PKC activation on GlyT1 regulation, we used three N-terminus GlyT1 isoforms stably expressed in porcine aortic endothelial (PAE) …

Isolation, Characterization And Molecular Cloning Of Dnase Iiib From Drosophila Melanogaster, Brenda Cristina Anchondo

Open Access Theses & Dissertations

Nucleases are enzymes that breakdown nucleic acids; they are classified by their biochemical properties into different groups (Evans et al., 2003). The ββα-Me finger family of nucleases are enzymes that combine structurally different groups but they are defined by a highly evolutionary conserved active site, a stretch of 22 amino acids composed by a β-hairpin (ββ) and α-helix (α) that anchor a catalytic metal ion (Sokolowska et al, 2009). Within this family is found the DNA/RNA non-specific nucleases. Nucleases that belong to the DNA/RNA non-specific group hydrolyze both ds and ss DNA, as well as RNA at equal or similar …

The Role Of Sumoylation Of Ledgf/P75 In Hiv-1 Infection, Murilo Tadeu Domingues Bueno

Open Access Theses & Dissertations

The lens epithelium-derived growth factor (LEDGF) proteins p75 and p52 are transcriptional co-activators that protect cells from stresses through modulation of stress and heat shock-related genes. Besides regulating such genes, LEDGF/p75 is also important in the process of HOX gene expression and leukemia transformation driven by the MLL histone methyl transferase complex. By exploiting a similar mechanism of interaction between LEDGF/p75 and MLL, the HIV-1 viral protein Integrase (IN) associates with LEDGF/p75 in order to execute efficient viral DNA integration. This present work has identified that LEDGF proteins are posttranslationally modified by SUMO-1 and -3. SUMOylation was found to target …

Antibactertial Property And Toxcity Study Of Medicinal Plant Tinospora Crispa L., Altammar Khadijah Ahmed Y.

Student Works (2010-2019)

Tinospora crispa is a medically important herb used for centuries in traditional medicine for the treatment of various ailments. The aim of this study was to investigate the safety of the aqueous and alcoholic extract of Tinospora crispa by determining its toxicological effects after acute administration in rats, and to investigate the antibacterial activity of both extracts. Disc diffusion and broth dilution methods were carried out in determining the antibacterial effects of the plant extract on the pure cultures of clinical isolates of 8 MRSA and S. aureus ATCC strain. The disc-diffusion method of the ethanolic extracts showed inhibition zone …

Post-Transcriptional Regulation Of Vibrio Cholerae Virulence Activator Toxt, Basel Hanna Abuaita

Wayne State University Dissertations

Vibrio cholera, the causative agent of the severe diarreal illness cholera, uses a complex array of gene regulation to induce its virulence determinants. During the early stage of infection, and upon response to unknown signals, virulence genes are turned on. ToxT protein is the primary virulence gene transcription activator. Once ToxT is produced, it amplifies its own expression through an auto-regulatory loop and directly binds and activates expression of various virulence factors including the toxin-coregulated pilus (TCP) and cholera toxin (CT). During the late stage of infection, virulence genes are turned off and the bacteria escape the host to resume …

Tracking Profiles Of Genomic Instability In Spontaneous Transformation And Tumorigenesis, Lesley Lawrenson

Wayne State University Dissertations

The dominant paradigm for cancer research focuses on the identification of specific genes for cancer causation and for the discovery of therapeutic targets. Alternatively, the current data emphasize the significance of karyotype heterogeneity in cancer progression over specific gene-based causes of cancer. Variability of a magnitude significant to shift cell populations from homogeneous diploid cells to a mosaic of structural and numerical chromosome alterations reflects the characteristic low-fidelity genome transfer of cancer cell populations. This transition marks the departure from micro-evolutionary gene-level change to macro-evolutionary change that facilitates the generation of many unique karyotypes within a cell population. Considering cancer …

The Interictal State In Epilepsy And Behavior, Daniel Tice Barkmeier

Wayne State University Dissertations

Epilepsy is one of the most common neurological diseases, affecting up to 1% of the world population. Epilepsy remains poorly understood and there are currently no medications to cure it. Patients with epilepsy have both seizures as well as another type of abnormal activity between seizures, known as interictal spikes. Interictal spikes have thus far been poorly researched, yet growing evidence supports an important role for them in epilepsy. In this project, we first show the high variability between reviewers in marking interictal spikes on intracranial EEG, and then develop and test an automated detection method to solve this problem. …

Evolution Of Lactate Dehydrogenase Genes In Primates, With Special Consideration Of Nucleotide Organization In Mammalian Promoters, Zack Papper

Wayne State University Dissertations

Concomitant with an increase in brain volume and mass, the allocation of energetic resources to the brain increased during stem anthropoid evolution, leading to humans. One mechanism by which this allocation may have occurred is through greater use of lactate as a neuronal fuel. Both the production of lactate, and conversion to pyruvate for use in aerobic metabolism, are catalyzed, in part, by the tetrameric enzyme lactate dehydrogenase (LDH). The two primary LDH genes, LDHA and LDHB, confer different rates of substrate turnover to the LDH enzyme, and these rates lend to the argument that LDHA supports anaerobic while LDHB …

Enzymology And Medicinal Chemistry Of N5-Carboxyaminoimidazole Ribonucleotide Synthetase : A Novel Antibacterial Target, Hanumantharao Paritala

Wayne State University Dissertations

N5-Carboxyaminoimidazole ribonucleotide synthetase (N5-CAIR synthetase), a key enzyme in microbial de novo purine biosynthesis, catalyzes the conversion of aminoimidazole ribonucleotide (AIR) to N5-CAIR. To date, this enzyme has been observed only in microorganisms, and thus, it represents an ideal target for antimicrobial drug development. Here we report structural and functional studies on the Aspergillus clavatus N5-CAIR synthetase and identification of inhibitors for the enzyme. In collaboration with Dr. Hazel Holden of the University of Wisconsin, the three-dimensional structure of Aspergillus clavatus N5-CAIR synthetase was solved in the presence of either Mg2ATP or MgADP and AIR. These structures, determined to 2.1 …

Characterization Of Arsd: An Arsenic Chaperone For The Arsab As(Iii)-Translocating Atpase, Jianbo Yang

Wayne State University Dissertations

Arsenic is a metalloid toxicant that is widely distributed throughout the earth's crust and causes a variety of health and environment problems. As an adaptation to arsenic-contaminated environments, organisms have developed resistance systems. In bacteria and archaea various ars operons encode ArsAB ATPases that pump the trivalent metalloids As(III) or Sb(III) out of cells. In these operons, an arsD gene is almost always adjacent to the arsA gene, suggesting a related function. ArsA is the catalytic subunit of the pump that hydrolyzes ATP in the presence of arsenite or antimonite. ArsB is a membrane protein which containing arsenite-conducting pathway. ArsA …

Regulatory And Functional Aspects Of Foxo3a Transcription Factor And Their Implications In Prostate Cancer, Melissa Elise Dobson

Wayne State University Dissertations

The P13K/Akt pathway is a critical mediator of growth factor signaling involving many cellular functions. The deregulation of this pathway has been shown to be involved in the development of various cancers. One of the main targets of this pathway is FoxO3a, a transcription factor whose target genes are involved in important cellular processes such as apoptosis, cell cycle control, and glucose metabolism. FoxO3a is regulated by various post translational modifications including acetylation, ubiquitination and phosphorylation. The transcription factor is directly phosphorylated by Akt on 3 residues: Threonine 32, Serine 253 and Serine 315. Phosphorylation by Akt generates binding sites …

Unraveling The Molecular Mechanisms Of Insect Diversity, Steven Michael Hrycaj

Wayne State University Dissertations

ABSTRACT

UNRAVELING THE MOLECULAR MECHANISMS OF INSECT DIVERSITY

by

STEVEN MICHAEL HRYCAJ

April 2010

Advisor: Dr. Aleksandar Popadic´

Major: Biological Sciences

Degree: Doctor of Philosophy

While it has long been recognized that the arthropods represent the most diverse animal phylum, the molecular bases defining these large-scale differences in body plans and appendages are only now becoming clear. Specifically, the recent merger between the fields of evolutionary and developmental biology ("evo-devo") have provided several examples illustrating that this extraordinary diversification may be due to evolved variation(s) in the developmental networks that control the formation of these structures. In addition, the delineation …

Polyomavirus Enhancer Activator 3 (Pea3), A Member Of The Ets Family Of Transcription Factors, Is A Transcriptional Activator Of Notch-1 And Notch-4 In Breast Cancer: An Opportunity For Novel Combinational Therapy, Anthony George Clementz

Dissertations

Women diagnosed with triple-negative breast cancer have the worst overall prognosis and frequently present with metastatic tumors. To date, there are no targeted therapies available to combat this aggressive form of breast cancer due to the lack of expression of well-known targets such as ER-alpha, PR, or HER2/neu. Therefore, there is an immediate need to identify novel targets that are responsible for the proliferation, survival, and invasive phenotype. Notch-1 and Notch-4, both potent breast oncogenes, are overexpressed in triple-negative breast cancers-associated with the poorest overall survival. PEA3 (polyomavirus enhancer activator 3), a member of the Ets family of transcription factors, …

The Role Of Ledgf/P75 In Transcriptional Regulation, Jeffrey Ryan Kugelman

Open Access Theses & Dissertations

The Lens Epithelial Derived Growth Factor p75 (LEDGF/p75) is a chromatin bound protein whose cellular function is not yet clearly known. A role in transcriptional regulation had been previously proposed based on its interaction with the basal transcriptional machinery and on its effects on the expression of genes involved in the cellular response to environmental stresses. To further elucidate the function of LEDGF/p75, we conducted a global and unbiased evaluation of the role of this protein in gene expression. To that aim, we performed a microarray analysis of cellular gene expression in cells that are severely depleted of LEDGF/p75. To …

Structural Investigation Of Atp-Utilizing Enzymes: Structures Involved In H+ Homeostasis And The Proliferation Of Hormone-Dependent Cancers, Zacariah Louis Hildenbrand

Open Access Theses & Dissertations

ATP is a multifunctional nucleotide considered to be the "molecular unit of currency" of intracellular energy transfer. ATP is utilized ubiquitously for the transport of chemical energy within the cell in addition to acting as a substrate in the regulation of many metabolic and signaling transduction pathways such as kinase-mediated signaling cascades. Interestingly, the functional mechanisms of many enzymes require the binding of ATP to trigger key structural and conformational changes that ultimately result in enzyme-directed catalysis. Two of the most omnipresent ATPases within the cell include the V-ATPase rotary proton pump and the Hsp90 protein-folding chaperone. Structural and biochemical …

P63 And Vdr Are Regulated By Vitamin D (Vd3) And Uv Signaling, Andrew J. Whitlatch

Browse all Theses and Dissertations

Skin cancers, such as squamous cell carcinoma (SCC), develop from accumulated mutations as a result of excessive exposure to Ultraviolet B (UVB) radiation. Intriguingly, UVB also catalyzes the synthesis of 1alpha, 25-dihydroxy Vitamin D3 (VD3), the hormonally active form of Vitamin D. Downstream VD3 signaling has been associated with promoting the inhibition of cell cycle progression, regulating calcium homeostasis, and inducing differentiation and apoptosis. VD3 mediates these processes via genomic mechanisms through interaction with its cognate receptor, the Vitamin D Receptor, (VDR). In addition, it was recently discovered that VD3 reduces UVB-mediated phosphorylation of the SAPK/c-Jun N-terminal kinase (JNK), which …

Inhibition Of Cell Invasion By Targeting Pld, Terry C. Farkaly

Browse all Theses and Dissertations

Phospholipase D (PLD) is a crucial signaling enzyme involved in many cellular processes. The catalytic activity of PLD is essential for the production of Phosphatidic Acid (PA), a critical second messenger in cell signaling cascades downstream. Using the highly invasive rat mammary adenocarcinoma cell line mTLn3 as a metastatic model, we investigated the proficiency of these cells to invade using matrigels that mimic the basement membrane of the extracellular matrix (ECM), their activity through PLD enzymatic assays, as well as the potency of our potential inhibitors to inhibit PLD-mediated cell invasion and lipase activity. This study reveals that PLD-mediated cell …

Genetic Studies Of Genes Involved In The Initiation Of Dna Replication In The Fission Yeast Schizosaccharomyces Pombe, Zhuo Wang

Browse all Theses and Dissertations

The initiation of DNA replication is a highly conserved process in all eukaryotes. However, the underlying mechanism is not well understood. Genetic studies in the fission yeast S. pombe have contributed greatly to and will continue to provide insights to our understanding of this important biological process.

In the first chapter, we have used a complementary method to test three recently identified human replication proteins DUE-B, Ticrr/Treslin, and GEMC1 as the candidate functional homologue of Sld3 in S. pombe. Sld3 is an essential replication initiation protein discovered in yeasts. Since no apparent sequence similarity can be found, its homologue in …

Characterization Of Three Mutations In Conserved Domain Of Subunit Iii Of Cytochrome C Oxidase From Rhodobacter Sphaeroides, Rachel Omolewu

Browse all Theses and Dissertations

Cytochrome c oxidase (COX) is the final electron acceptor in mitochondrial respiratory chain and in many bacterial species including Rhodobacter sphaeroides. Electron transfer is coupled with the pumping of protons across the membrane. Previous work has shown that reaction of beef COX with dicyclohexylcarbodiimide (DCCD) resulted in an inhibition of proton translocation by covalently binding to the conserved amino acid residue E90 located in a nonpolar region of subunit III (SIII). E90 is involved in a bonding pair with another conserved residue H212, possibly connected by a salt bridge or a hydrogen bond in the three dimensional structure of SIII. …

Induction Of Interferon And Interferon Signaling Pathways By Replication Of Defective Interfering Particle Rna In Cells Constitutively Expressing Vesicular Stomatitis Virus Replication Proteins, Debasis Panda, Phat X. Dinh, Lalit Beura, Asit K. Pattnaik

School of Veterinary and Biomedical Sciences: Faculty Publications

We show here that replication of defective interfering (DI) particle RNA in HEK293 cells stably expressing vesicular stomatitis virus (VSV) replication proteins potently activates interferon (IFN) and IFN signaling pathways through upregulation of IFN- promoter, IFN-stimulated response element (ISRE) promoter, and NF-κB promoter activities. Replication of DI particle RNA, not mere expression of the viral replication proteins, was found to be critical for induction of IFN and IFN signaling. The stable cells supporting replication of DI RNA described in this report will be useful in further examining the innate immune signaling pathways and the host cell functions in viral genome …

Towards An Understanding Of The Herpes Simplex Virus Type 1 Latency-Reactivation Cycle, Guey-Chuen Perng, Clinton Jones

School of Veterinary and Biomedical Sciences: Faculty Publications

Infection by herpes simplex virus type 1 (HSV-1) can cause clinical symptoms in the peripheral and central nervous system. Recurrent ocular shedding can lead to corneal scarring and vision loss making HSV-1 a leading cause of corneal blindness due to an infectious agent. The primary site of HSV-1 latency is sensory neurons within trigeminal ganglia. Periodically, reactivation from latency occurs resulting in virus transmission and recurrent disease. During latency, the latency-associated transcript (LAT) is abundantly expressed. LAT expression is important for the latency-reactivation cycle in animal models, in part, because it inhibits apoptosis, viral gene expression, and productive infection. A …

Method For Identification Of Virulence Determinants, Raul G. Barletta, Beth Harris

School of Veterinary and Biomedical Sciences: Faculty Publications

Disclosed are methods for the determination of virulence determinants in bacteria and in particular bacteria of the genus Mycobacterium. Also disclosed are compositions and methods for stimulating an immune response in an animal using bacteria and virulence determinants identified by the methods of the present invention.