Biochemistry, Biophysics, and Structural Biology Commons^™

Evolution Of New Enzymatic Function By Structural Modulation Of Cysteine Reactivity In Pseudomonas Fluorescens Isocyanide Hydratase, Mahadevan Lakshminarasimhan, Peter Madzelan, Ruth Nan, Nicole Marie Milkovic, Mark A. Wilson

Department of Biochemistry: Faculty Publications

Isocyanide (formerly isonitrile) hydratase (EC 4.2.1.103) is an enzyme of the DJ-1 superfamily that hydrates isocyanides to yield the corresponding N-formamide. In order to understand the structural basis for isocyanide hydratase (ICH) catalysis, we determined the crystal structures of wild-type and several site-directed mutants of Pseudomonas fluorescens ICH at resolutions ranging from 1.0 to 1.9 Å. We also developed a simple UV-visible spectrophotometric assay for ICH activity using 2-naphthyl isocyanide as a substrate. ICH contains a highly conserved cysteine residue (Cys101) that is required for catalysis and interacts with Asp17, Thr102, and an ordered water molecule in the active …

Identification Of Deletion Mutants Of Inositol Kinases And Phosphatases Hypersensitive To Valproate, W-Mudiyanselage Manoj Senaka Bandara

Wayne State University Theses

ABSTRACT

IDENTIFICATION OF DELETION MUTANTS OF INOSITOL KINASES AND PHOSPHATASES HYPERSENSITIVE TO VALPROATE

by

WELLEWATTA MUDIYANSELAGE MANOJ SENAKA BANDARA

MAY 2010

Advisor: Dr. Miriam Greenberg

Major: Biological Sciences

Degree: Master of Science

Bipolar disorder (BD) is a chronic psychiatric illness affecting at least 1% of the world population. BD is ranked as the sixth greatest cause of death or disability globally. The cause of BD is unknown. Although the anticonvulsant valproate (VPA) is widely used as a mood stabilizer to treat BD, VPA is not completely effective and causes numerous side effects. Hence, it is important to develop more effective …

Molecular Identification Of Arowana Species Based On Cytochrome B And Cytochrome C Oxidase I (Coi) / Maryam Zahedi Fard, Maryam Zahedi Fard

Student Works (2010-2019)

Mitochondrial DNA (mtDNA) markers has been widely used to better resolve the taxonomic identification as well as display the genetic relatedness of different species and closely related fish. The highly cost ornamental fish, Asian arowana (Scleropages formosus) of family Osteoglossidae has different colored strains that are geographically distributed in different regions around Southeast Asia. The taxonomic classification of these different strains still remains unclear and disputable. The partial sequences of the cytochrome b and the DNA barcoding gene, cytochrome C oxidase were analyzed and assessed for molecular identification; to differentiate the colored varieties of this species. The results of this …

Human Health Relies On Proper Cellular Communication, Which Starts With Protein Recognition, Zaharah Rossi, Bella Lonardo

Research on Capitol Hill

Cells Have Rules For Communication

Just like humans have rules about how to communicate within a society, cells also need rules to govern communication. 

Protein Arginine Methyltransferases (PRMTs) are enzymes that make modifications to specific proteins in a cell to communicate. Importantly, PRMTs need to distinguish a target protein from a non-target protein.

The Roles Of Rhle And Hfq In Srna-Dependent Gene Regulation, Abeykoon Jayalath Iresha Sandeepanie Rathnayake

Wayne State University Theses

THE ROLES OF RHLE AND HFQ IN SRNA-DEPENDENT GENE REGULATION

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ABEYKOON JAYALATH IRESHA SANDEEPANIE RATHNAYAKE

DECEMBER 2010

Advisor: Dr. Andrew Feig

Major: Chemistry

Degree: Master of Science

Bacteria are adapted to live in diverse environmental conditions. Thus, they show excellent tolerance and response to extreme environmental conditions caused by low or high temperatures, high salinity, reactive oxygen species or high nutrient concentrations. sRNAs have been identified and characterized as cis-acting or trans-acting post-transcriptional regulators in diverse cellular processes including virulence and adaptation to environmental stress (11,12,14,15). Interactions of sRNAs and target mRNAs result in translational repression, translational activation or/and …

Creg1 And Its Enhancement Of P16ink4a-Induced Senescence, Benchamart Moolmuang

Wayne State University Dissertations

Bypassing cellular senescence, an irreversible growth arrest of cells that is activated in normal cells to become immortal is one of the prerequisites for carcinogenesis. Cellular senescence can be triggered by shortening of telomeres and certain cellular stresses. Using spontaneously immortalized Li-Fraumeni Syndrome (LFS) fibroblasts, we found that CREG1 (Cellular Repressor of E1A-stimulated Genes1) is one of genes whose expression fit the criteria of senescence-associated genes, decreased expression during immortalization and increased in senescence. Moreover, we found that epigenetic mechanisms regulate CREG1 expression in LFS fibroblasts. CREG1 is a secreted glycoprotein that was shown to bind Rb-family pocket proteins and …

Group Ii Intron Dynamics In Heterologous Hosts, Venkata Raghavendra Aditya Chalamcharla

Legacy Theses & Dissertations (2009 - 2024)

Group II introns are ribozymes with an innate ability to self-splice. They are found predominantly in bacterial and bacterial-derived organellar genomes, but not in the nuclear genomes of eukaryotes. In bacteria, group II introns often behave as mobile retroelements, invading host DNA and exploiting its machinery to complete the retromobility process. The object of my studies is the group II intron found in the Lactococcus lactis relaxase gene. To determine the nature of the group II intron-host relationship, we performed a genetic screen and identified several host factors that affect group II intron retromobility in Escherichia coli, which provides a …

Preparation And Application Of Transgenic And Knockout Mouse Models For Studies On Cytochrome P450 Functions, Yuan Wei

Legacy Theses & Dissertations (2009 - 2024)

The overall objective of this dissertation is to study the in vivo function of microsomal cytochrome P450 monooxygenases (P450s), which metabolize numerous drugs, chemical carcinogens, environmental pollutants, as well as endogenous signaling molecules such as steroid hormones and eicosanoids. The major research tool of this study involves the development of transgenic and knockout mouse models. The specific aims are 1) to study the in vivo function of NADPH-cytochrome P450 reductase (CPR) and CPR-dependent enzymes using a mouse model with a reversible hypomorphic Cpr gene; 2) to study the in vivo function of CYP2A13 with a CYP2A13- transgenic model; and 3) …

The Alliinase And Lachrymatory Factor Synthase Systems In Petiveria Alliacea, Quan He

Legacy Theses & Dissertations (2009 - 2024)

Isolation and characterization of an alliinase and a lachrymatory factor synthase from the Amazonian medicinal plant Petiveria alliacea is reported. The alliinase is unusual in that it is heteromeric, whereas all previous reports of characterized alliinases have shown them to be monomers or homomultimers. The protein possesses 5 subunits: two alpha subunits which are glycosylated and connected by a disulfide bond, and beta, gamma and delta subunits. The alliinase exhibits broad substrate specificity, reacting with S-substituted-L-cysteine sulfoxides with aromatic, aliphatic, alkenyl and polar side chains. The alliinase-mediated breakdown of a variety of cysteine sulfoxide derivatives yields transitory sulfenic acid intermediate …

Saturation Transfer Difference Nmr Studies : Pyrazinamide And Pyrazinamide Analogs Coordinating With Mycobacterium Tuberculosis Fatty Acid Synthase I (Fas I), Halimah Sayahi

Legacy Theses & Dissertations (2009 - 2024)

One third of the world's population is infected with M. tuberculosis, the causative agent of tuberculosis (TB) that claims the life of approximately 2 million people every year. The rapid spread of multidrug-resistance tuberculosis as well the emergence of extensively drug resistance strains that are resistant to virtually any known antibiotic, has transformed this once curable disease into a major public health challenge. To regain control of this disease and the associated mortality and morbidity new antibiotics are urgently needed.

Elucidating The Structure Of Protein Aggregates By Raman Spectroscopy, Ludmila A. Popova

Legacy Theses & Dissertations (2009 - 2024)

The structures and properties of amyloid fibrils are of considerable interest due to their associations with numerous neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease and transmissible spongiform encephalopaties (prion diseases). Understanding fibrillogenesis at a molecular level requires detailed structural characterization of amyloid fibrils. However amyloid fibrils are difficult objects to study due to their non-crystalline and insoluble nature. These properties make the application of classical tools of structural biology, such as X-Ray crystallography and solution Nuclear Magnetic Resonance spectroscopy, impractical for structural characterization of protein fibrils.

Morphological Changes And Immunohistochemical Expression Of Rage And Its Ligands In The Sciatic Nerve Of Hyperglycemic Pig (Sus Scrofa), Judyta K. Juranek, Alexey Aleshin, Eileen M. Rattigan, Lynne Johnson, Wu Qu, Fei Song, Radha Ananthakrishnan, Nosirudeen Quadri, Shi Du Yan, Ravichandran Ramasamy, Ann Marie Schmidt, Matthew S. Geddis

Publications and Research

The aim of our project was to study the effect of streptozotocin (STZ)—induced hyperglycemia on sciatic nerve morphology, blood plasma markers and immunohistochemical expression of RAGE (the Receptor for Advanced Glycation End-products), and its ligands—S100B and Carboxymethyl Lysine (CML)-advanced glycation endproduct (AGE) in the laboratory pig. Six months after STZ—injections, blood plasma measurements, morphometric analysis of sciatic nerve fiber density, immunofluorescent distribution of potential molecular neuropathy contributors, ELISA measurement of plasma AGE level and HPLC analysis of sciatic nerve levels of one of the pre-AGE and the glycolysis intermediate products—methyl-glyoxal (MG) were performed. The results of our study revealed that …

Uncultivated Environmental Tm7 Model To Study Human Disease-Associated Tm7 Bacteria, David Barton

Master's Theses

The TM7 bacterial phylum has no cultivated species and includes members that span a broad range of environmental and human habitats, some of which are associated with human periodontitis. In this project, activated wastewater TM7 bacteria were analyzed and their relatedness compared to human-associated TM7 bacteria for the long-term goal of using an environmental TM7 to better understand TM7 pathogenesis in humans. DNA was extracted from activated wastewater and PCR amplified using TM7 16S rRNA gene- specific primers. The ~1,170 base pair PCR products were then cloned and sequenced. DNA sequencing and phylogenetic analysis identified environmental TM7 clones with high …

Investigating The Metal Binding Sites In Znta, A Zinc Transporting Atpase, Sandhya Muralidharan

Wayne State University Dissertations

ZntA from Escherichia coli is a member of the P_IBtype ATPase family of transporters. The P_IB-type ATPase pumps maintain cellular homeostasis of heavy metals such as Zn²⁺, Co²⁺, Cu²⁺, Cu⁺, and mediate resistance to toxic metals such as Pb²⁺, Cd²⁺ and Ag⁺. ZntA confers resistance to Pb²⁺, Cd²⁺, and Zn²⁺ by pumping these ions out of the cytoplasm. ZntA has two metal binding sites, one in the hydrophilic N-terminal domain and the other in the transmembrane region. The …

Towards An Understanding Of The Etiology Of Abdominal Aortic Aneurysms: Identification Of Genes Implicated In Aaa Risk And Development, John Hunt Lillvis

Wayne State University Dissertations

Abdominal aortic aneurysm (AAA) is a common disease for which mechanisms of formation are still not well understood. Despite a strong genetic component to AAA risk, specific risk alleles are still largely unidentified. AAA is also a localized disease with a majority occurring in the infrarenal abdominal aorta and is six times more common than aneurysms of the thoracic aorta. To determine whether risk alleles are present in functional positional candidate genes. we: 1. performed a genetic association study using DNA from AAA cases and controls in ten candidate genes and 2. performed exon sequencing on three genes with evidence …

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 …

Frustrated Drift Of An Anchored Scroll-Wave Filament And The Geodesic Principle, Marcel Wellner, Christian W. Zemlin, Arkady M. Pertsov

Bioelectrics Publications

We investigate anchored scroll-wave filaments in an excitable medium whose diffusivity matrix, including its determinant, is spatially nonuniform. The study is motivated by cardiological applications where scroll-wave behavior in the presence of diffusivity gradients is believed to play an important role in the development of severe arrhythmias. A diffusivity gradient is expected to make the filament drift, unless drift is prevented ("frustrated") by anchoring to localized defects in the propagation medium. The resulting stationary filament is a geodesic curve, as demonstrated here in the case of a nonzero but constant gradient. That is, the diffusivity matrix has a determinant that …

Prospects And Pits On The Path Of Biomimetics: The Case Of Tooth Enamel, Vuk Uskoković

Pharmacy Faculty Articles and Research

This review presents a discourse on challenges in understanding and imitating the process of amelogenesis in vitro on the molecular scale. In light of the analysis of imitation of the growth of dental enamel, it also impends on the prospects and potential drawbacks of the biomimetic approach in general. As the formation of enamel proceeds with the protein matrix guiding the crystal growth, while at the same time conducting its own degradation and removal, it is argued that three aspects of amelogenesis need to be induced in parallel: a) crystal growth; b) protein assembly; c) proteolytic degradation. A particular emphasis …