Biochemistry, Biophysics, and Structural Biology Commons^™

Evidence For A Pro-Oxidant Intermediate In The Assembly Of Cytochrome Oxidase, Oleh Khalimonchuk, Amanda Bird, Dennis R. Winge

Department of Biochemistry: Faculty Publications

The hydrogen peroxide sensitivity of cells lacking two proteins,

Sco1 and Cox11, important in the assembly of cytochrome

c oxidase (CcO), is shown to arise from the transient accumulation

of a pro-oxidant heme A-Cox1 stalled intermediate. The

peroxide sensitivity of these cells is abrogated by a reduction in

either Cox1 expression or hemeAformation but exacerbated by

either enhanced Cox1 expression or heme A production arising

from overexpression of COX15. Sco1 and Cox11 are implicated

in the formation of the Cu_A and Cu_B sites of CcO, respectively.

The respective wild-type genes suppress the peroxide sensitivities

of sco1∆ …

Coa1 Links The Mss51 Post-Translational Function To Cox1 Cofactor Insertion In Cytochrome C Oxidase Assembly, Fabien Pierrel, Megan L. Bestwick, Paul A. Cobine, Oleh Khalimonchuk, Julia A. Cricco, Dennis R. Winge

Department of Biochemistry: Faculty Publications

The assembly of cytochrome c oxidase (CcO) in yeast mitochondria is shown to be dependent on a new assembly factor designated Coa1 that associates with the mitochondrial inner membrane. Translation of the mitochondrial-encoded subunits of CcO occurs normally in coa1Δ cells, but these subunits fail to accumulate. The respiratory defect in coa1Δ cells is suppressed by high-copy MSS51, MDJ1 and COX10. Mss51 functions in Cox1 translation and elongation, whereas Cox10 participates in the biosynthesis of heme a, a key cofactor of CcO. Respiration in coa1Δ and shy1Δ cells is enhanced when Mss51 and …

Sulfite Reduction In Mycobacteria, Rachel Pinto, Joseph S. Harrison, Tsungda Hsu, William R. Jacobs Jr., Thomas S. Leyh

College of the Pacific Faculty Articles

Mycobacterium tuberculosis places an enormous burden on the welfare of humanity. Its ability to grow and its pathogenicity are linked to sulfur metabolism, which is considered a fertile area for the development of antibiotics, particularly because many of the sulfur acquisition steps in the bacterium are not found in the host. Sulfite reduction is one such mycobacterium-specific step and is the central focus of this paper. Sulfite reduction in Mycobacterium smegmatis was investigated using a combination of deletion mutagenesis, metabolite screening, complementation, and enzymology. The initial rate parameters for the purified sulfite reductase from M. tuberculosis were determined under strict …

Beta-Lactamase: An Ideal Reporter System For Monitoring Gene Expression In Live Eukaryotic Cells, Sohail A. Qureshi

Department of Biological & Biomedical Sciences

To gain insightful information about the mechanisms through which genes are activated and repressed requires gene reporter systems that are sensitive, robust, and cost-effective. Although numerous reporter gene technologies are commercially available, none are as sophisticated and user-friendly as beta-lactamase (BLA) when it comes to studying gene expression in live cells. This article presents an overview of the BLA technology and describes how it can be exploited for studying rare events such as homologous recombination in somatic cells and be used to deliver any DNA sequence of choice anywhere within the genome.

The Effect Of 1,25-Dihydroxy Vitamin D3 On At1 Cell Receptor Expression In Human Iliac Artery Endothelial Cells (Hiaec), Jenny Thomas

Theses and Dissertations

The renin-angiotensin system (RAS) plays an important part in homeostasis through angiotensin IPs role as a vasoconstrictor. Defects in the renin angiotensin system can lead to hypertension, heart attack, and stroke (Weir, 1999). Studies have shown an inverse relationship between Vitamin D3 and blood pressure (Li et al., 2002). While studies have been performed on vitamin D's effect on renin expression, little is known about vitamin D's effect on the angiotensin II high-affinity type 1 (ATi) receptor. The hypothesis for this study was that human iliac artery endothelial cells (HIAEC) supplemented with 1,25-dihydroxy vitamin D3 will express less AT] receptor …

The Application Of Electrospray Ionization Coupled To Ultrahigh Resolution Mass Spectrometry For The Molecular Characterization Of Natural Organic Matter, Rachel L. Sleighter, Patrick G. Hatcher

Chemistry & Biochemistry Faculty Publications

Mass spectrometry has recently played a key role in the understanding of natural organic matter (NOM) by providing molecular-level details about its composition. NOM, a complex assemblage of organic molecules present in natural waters and soils/sediments, has the ability to bind and transport anthropogenic materials. An improved understanding of its composition is crucial in order to understand how pollutants interact with NOM and how NOM cycles through global carbon cycles. In the past, low-resolution (> 3000) mass analyzers have offered some insights into the structure of NOM, but emerging ultrahigh resolution (> 200000) techniques such as electrospray ionization (ESI) coupled …

Mutations In Transmembrane Domains 1, 4 And 9 Of The Plasmodium Falciparum Chloroquine Resistance Transporter Alter Susceptibility To Chloroquine, Quinine And Quinidine, Roland A. Cooper, Kristan D. Lane, Bingbing Deng, Jianbing Mu, Jigar J. Patel, Thomas E. Wellems, Xinzhuan Su, Michael T. Ferdig

Biological Sciences Faculty Publications

Mutations in the Plasmodium falciparum chloroquine (CQ) resistance transporter (PfCRT) can result in verapamil-reversible CQ resistance and altered susceptibility to other antimalarials. PfCRT contains 10 membrane-spanning domains and is found in the digestive vacuole (DV) membrane of intraerythrocytic parasites. The mechanism by which PfCRT mediates CQ resistance is unclear although it is associated with decreased accumulation of drug within the DV. On the permissive background of the P. falciparum 106/1(K76) parasite line, we used single-step drug selection to generate isogenic clones containing unique pfcrt point mutations that resulted in amino acid changes in PfCRT transmembrane domains 1 (C72R, K76N, K76I …

In Vivo Imaging Of Transport And Biocompatibility Of Single Silver Nanoparticles In Early Development Of Zebrafish Embryos, Kerry J. Lee, Prakash D. Nallathamby, Lauren M. Browning, Christopher J. Osgood, Xiao-Hong Nancy Xu

Chemistry & Biochemistry Faculty Publications

Real-time study of the transport and biocompatibility of nanomaterials in early embryonic development at single-nanoparticle resolution can offer new knowledge about the delivery and effects of nanomaterials in vivo, and provide new insights into molecular transport mechanisms in developing embryos. In this study, we directly characterized the transport of single silver nanoparticles into an in vivo model system (zebrafish embryos) and investigated their effects on early embryonic development at single-nanoparticle resolution in real time. We designed highly purified and stable (not aggregated and no photodecomposition) nanoparticles and developed single-nanoparticle optics and in vivo assays to enable the study. We …

The Role Of Sphingosine Kinase 2 In Cell Growth And Apoptosis, Heidi M. Sankala

Theses and Dissertations

Two isoforms of sphingosine kinase (SphK) catalyze the formation of sphingosine-1-phosphate (SIP). Whereas, SphKl stimulates cell growth and survival, it was found that when overexpressed in mouse NIH 3T3 fibroblasts SphK2 enhances caspase-dependent apoptosis in response to serum deprivation, independently of S1P receptors. Sequence analysis revealed that SphK2 contains a 9 amino acid motif similar to that present in BH3-only proteins. Studies showed that the BH3-only domain, catalytic activity, endoplasmic reticulum (ER) stress, and uptake of calcium by the mitochondria may all contribute to the apoptotic effects of overexpressed SphK2 in NIH 3T3 cells. Further studies in human carcinoma cells …

The Influence Of Adenoviral Infection And The Group Via Calcium-Independent Phospholipase A2 On Hepatic Lipid Metabolism, William Palmer Wilkins Iii

Theses and Dissertations

Sterol regulatory element-binding proteins (SREBP) are transcription factors that regulate genes involved in lipid metabolism especially in the liver. Therefore, hepatic SREBP is significant regulator of systemic lipid metabolism. Evidence demonstrates that insulin and dietary unsaturated fatty acid (UFA) regulate SREBP1 expression and subsequent SREBP1-mediated gene transcription, events that in many instances result in modulation of systemic fatty acid and triglyceride (TG) homeostasis. A series of investigations was designed to uncover novel regulators of SREBP1. Dietary and exogenous addition of UFA has been shown to regulate SREBP function yet, an endogenous source of UFA capable of modulating SREBP remains elusive. …

Characterization Of Power Induced Heating And Damage In Fiber Optic Probes For Near-Field Scanning Optical Microscopy, Nicholas E. Dickenson, E. S. Erickson, O. L. Mooren, R. C. Dunn

Chemistry and Biochemistry Faculty Publications

Tip-induced sample heating in near-field scanning optical microscopy (NSOM) is studied for fiber optic probes fabricated using the chemical etching technique. To characterize sample heating from etched NSOM probes, the spectra of a thermochromic polymer sample are measured as a function of probe output power, as was previously reported for pulled NSOM probes. The results reveal that sample heating increases rapidly to ~55–60°C as output powers reach ~50 nW. At higher output powers, the sample heating remains approximately constant up to the maximum power studied of ~450 nW. The sample heating profiles measured for etched NSOM probes are consistent with …

Due-B In Chromatin And Nuclear Speckles, Nadia Katrangi

Browse all Theses and Dissertations

The DNA unwinding element binding protein (DUE-B) was first identified by using a yeast one hybrid screen with the DNA unwinding element (DUE) from the c-myc origin as bait. DUE-B's orthologue in the yeast Saccharomyces cerevisiae lacks the last 60 C-terminal amino acids and has been identified as a D-tyrosyl-tRNA deacylase. A substantial group of evidence suggests a role for DUE-B in the regulation of replication initiation. Here we show that DUE-B is focused in nuclear speckles and colocalizes with spliceosome associated protein 145 (SAP145), an mRNA splicing factor 3B subunit. Mass spectrometry results show that SAP145 co-purifies with the …

Vglut And Gad65 Expression In Physiologically Characterized Ia Afferents, Ivonne Nkoli Ukpabi

Browse all Theses and Dissertations

Peripheral nerve injury is known to induce several changes in the physiology and morphology of the injured afferent. These changes include hyperexcitability, decreased dorsal root potentials (DRP), loss of synaptic vesicles as well as loss of the vesicular glutamate transporter, VGLUT1. While many of the changes caused by peripheral injury revert with regeneration, others appear to be permanent. The loss of the stretch reflex for example is a puzzling outcome of recovery after peripheral nerve transection and regeneration, especially given that the electrical counterpart of the stretch reflex (the H-reflex) recovers after regeneration. We hypothesized that stretch induced transmission is …

To Establish Accurate Local Adult Reference Ranges For Routine Chemistries In A Large Diagnostic Clinical Biochemistry Laboratory In The Hse South Area, Barbara Kenneally

Theses

The objectives of this project were:

i. To establish adult reference ranges for routine chemistries quoted in the Clinical Biochemistry Department, Cork University Hospital (CUH), by using samples from blood donors at the local blood bank. 120 samples of blood from male blood donors and 120 samples from female blood donors were collected from the Irish Blood Transfusion Service (Cork). These samples were analysed for 21 routine chemistry analytes, using non-parametric statistics.

ii. To study the statistics of nineteen routine chemistries of the adult population served by the laboratory over a one- month period. Results were collected for each of …

Resistance Of The Target Islet Tissue To Autoimmune Destruction Contributes To Genetic Susceptibility In Type 1 Diabetes., Natasha J. Hill, Aleksandr Stotland, Michelle Solomon, Patrick Secrest, Elizabeth Getzoff, Nora Sarvetnick

Journal Articles: Regenerative Medicine

Type 1 diabetes occurs when self-reactive T lymphocytes destroy the insulin-producing islet beta cells of the pancreas. The defects causing this disease have often been assumed to occur exclusively in the immune system. We present evidence that genetic variation at the Idd9 diabetes susceptibility locus determines the resilience of the targets of autoimmunity, the islets, to destruction. Susceptible islets exhibit hyper-responsiveness to inflammatory cytokines resulting in enhanced cell death and increased expression of the death receptor Fas. Fas upregulation in beta cells is mediated by TNFR2, and colocalization of TNFR2 with the adaptor TRAF2 in NOD beta cells is altered. …

Detection And Destruction Of Escherichia Coli Bacteria And Bacteriophage Using Biofunctionalized Nanoshells, Joseph E. Van Buren

Browse all Theses and Dissertations

The ability to detect chemical and biological agents is arguably one of the highest priority technical challenges today. The capability to obtain specific information at and near single-molecule resolution is the ultimate goal in chemical and biological agent detection. Metallic nanostructures, nanoshells and nanorods in particular, are attractive substrates because of their plasmonic properties. Combining the specificity of biomolecular recognition with these nanostructures might lead to increased sensitivity and selectivity. Localization of biological recognition motifs to the surface of these nanostructures could provide a mechanism for highly specific and directed energy transfer when bound to its target. This study utilizes …

Differential Effects Of Mutant Tap63Γ On Transactivation Of P53 And/Or P63 Responsive Genes And Their Effects On Global Gene Expression, Shama Khan Khokhar

Browse all Theses and Dissertations

p63, a member of the p53 gene family, known to play a role in development, has more recently also been implicated in cancer progression. Mice lacking p63 exhibit severe developmental defects such as limb truncations, abnormal skin, and absence of hair follicles, teeth, and mammary glands. Germline missense mutations of p63 have been shown to be responsible for several human developmental syndromes including SHFM, EEC and ADULT syndromes and are associated with anomalies in the development of organs of epithelial origin. The contrasting phenotypes associated with the different classes of p63 mutations might be in part due to the differential …

The Biophysical Analysis Of The Human Telomeric Repeat (Ttaggg)4 And Characterization Of Porphyrin Binding In Potassium Solutions, Cosimo Antonacci

Seton Hall University Dissertations and Theses (ETDs)

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Differential Engagement Of Tim-1 During Activation Can Positively Or Negatively Costimulate T Cell Expansion And Effector Function, Vijay K. Kuchroo, Sheng Xiao, Nader Najafian, Jay Reddy, Monica Albin, Chen Zhu, Eric Jensen, Jaimie Imitola, Thomas Korn, Ana C. Anderson, Zheng Zhang, Cristina Gutierrez, Thomas Moll, Raymond A. Sobel, Dale T. Umetsu, Hideo Yagita, Hisaya Akiba, Terry Strom, Mohamed H. Sayegh, Rosemarie H. Dekruyff, Samia J. Khoury

School of Veterinary and Biomedical Sciences: Faculty Publications

It has been suggested that T cell immunoglobulin mucin (Tim)-1 expressed on T cells serves to positively costimulate T cell responses. However, crosslinking of Tim-1 by its ligand Tim-4 resulted in either activation or inhibition of T cell responses, thus raising the issue of whether Tim-1 can have a dual function as a costimulator. To resolve this issue, we tested a series of monoclonal antibodies specifi c for Tim-1 and identifi ed two antibodies that showed opposite functional effects. One anti–Tim-1 antibody increased the frequency of antigen-specifi c T cells, the production of the proinfl ammatory cytokines IFN-γ and IL-17, …

Identification Of Functional Subclasses In The Dj-1 Superfamily Proteins, Ying Wei, Dagmar Ringe, Mark A. Wilson, Mary Jo Ondrechen

Department of Biochemistry: Faculty Publications

Genomics has posed the challenge of determination of protein function from sequence and/or 3-D structure. Functional assignment from sequence relationships can be misleading, and structural similarity does not necessarily imply functional similarity. Proteins in the DJ-1 family, many of which are of unknown function, are examples of proteins with both sequence and fold similarity that span multiple functional classes. THEMATICS (theoretical microscopic titration curves), an electrostatics-based computational approach to functional site prediction, is used to sort proteins in the DJ-1 family into different functional classes. Active site residues are predicted for the eight distinct DJ-1 proteins with available 3-D structures. …

A New Strategy For Assessing Selenoprotein Function: Sirna Knockdown/Knock-In Targeting The 3'-Utr, Min-Hyuk Yoo, Xue-Ming Xu, Anton A. Turanov, Bradley A. Carlson, Vadim N. Gladyshev, Dolph L. Hatfield

Department of Biochemistry: Faculty Publications

Selenocysteine insertion into protein in mammalian cells requires RNA elements in the 3'-untranslated regions (3'-UTRs) of selenoprotein genes. The occurrence of these conserved sequences should make selenoproteins particularly amenable for knockdown/knock-in strategies to examine selenoprotein functions. Herein, we utilized the 3'-UTR of various selenoproteins to knock down their expression using siRNAs and then knock in expression using constructs containing mutations within the target region. Thioredoxin reductase 1 (TR1) knockdown in a mouse kidney cell line resulted in the cells growing about 10% more slowly, being more sensitive to UV radiation, and having increased apoptosis in response to UV than control …

Role Of Ceramide-1-Phosphate As A Specific And Potent Activator Of Group Iva Cytosolic Phospholipase A2 Alpha, Preeti Subramanian

Theses and Dissertations

Eicosanoids are potent mediators of inflammatory response whose role has been well established in inflammatory disorders. Release of arachidonic acid by group IVA cytosolic phospholipase A2 α (cPLA2α) is the initial rate limiting step for the production of eicosonoids in response to inflammatory mediators. Previous findings from our laboratory have demonstrated that cPLA2α is directly activated by the emerging bioactive sphingolipid, ceramide-1-phosphate (C1P). In this study, we have developed a modified Triton X-100/phosphatidylcholine (PC) mixed micelle assay which was utilized to determine the kinetics and specificity of this lipid-enzyme interaction. Using this assay, the activity of the enzyme increased in …

A Peroxisomal Acyltransferase In Mouse Identifies A Novel Pathway For Taurine Conjugation Of Fatty Acids., Sarah-Jayne Reilly, Eithne O'Shea, O'Byrne James, Stefan Alexson, Mary Hunt

Articles

A wide variety of endogenous carboxylic acids and xenobiotics are conjugated with amino acids, before excretion in urine or bile. The conjugation of carboxylic acids and bile acids with taurine and glycine has been widely characterized and de-novo synthesized bile acids are conjugated to either glycine or taurine in peroxisomes. Peroxisomes are also involved in the oxidation of several other lipid molecules, such as very long chain acyl-CoAs, branched chain acyl-CoAs and prostaglandins. In this study we have now identified a novel peroxisomal enzyme called acyl-CoA:amino acid N-acyltransferase (ACNAT1). Recombinantly expressed ACNAT1 acts as an acyltransferase that efficiently conjugates very …

Peroxisomes Contain A Specific Phytanoly-Coa/Pristanoyl-Coa Thioesterase Acting As A Novel Auxiliary Enzyme In Alpha-And Beta-Oxidation Of Methyl-Branched Fatty Acids In Mouse, Maria Westin, Mary Hunt, Stefan Alexson

Articles

Phytanic acid and pristanic acid are derived from phytol, which enter the body via the diet. Phytanic acid contains a methyl group in position three and therefore cannot undergo b-oxidation directly, but instead must first undergo a-oxidation to pristanic acid, which then enters b-oxidation. Both these pathways occur in peroxisomes, and in this study we have identified a novel peroxisomal acyl-CoA thioesterase, named ACOT6, which we show is specifically involved in phytanic acid and pristanic acid metabolism. Sequence analysis of ACOT6 revealed a putative peroxisomal targeting signal at the C-terminal end, and cellular localization experiments verified it as a peroxisomal …

A Proteome-Wide Protein Interaction Map For Campylobacter Jejuni, Jodi R. Parrish, Jingkai Yu, Guozhen Liu, Julie A. Hines, Jason E. Chan, Bernie A. Mangiola, Huamei Zhang, Svetlana Pacifico, Farshad Fotouhi, Victor J. Dirita, Trey Ideker, Phillip Andrews, Russell L. Finley Jr

Wayne State University Associated BioMed Central Scholarship

Abstract

Background

Data from large-scale protein interaction screens for humans and model eukaryotes have been invaluable for developing systems-level models of biological processes. Despite this value, only a limited amount of interaction data is available for prokaryotes. Here we report the systematic identification of protein interactions for the bacterium Campylobacter jejuni, a food-borne pathogen and a major cause of gastroenteritis worldwide.

Results

Using high-throughput yeast two-hybrid screens we detected and reproduced 11,687 interactions. The resulting interaction map includes 80% of the predicted C. jejuni NCTC11168 proteins and places a large number of poorly characterized proteins into networks that provide initial …

Development Of An Immunoturbidimetric Particle Enhanced Assay For Detection Of C-Reactive Protein, Maria Nicholas

Theses

Background: C-reactive protein (CRP) is a well-known marker for inflammation. Recent studies have demonstrated that increases in CRP concentrations are associated with future coronary events in apparently healthy men and women. The requirement for assays, capable of testing CRP concentrations within the range 1-lOmg/l, is therefore great.

Methods: Two CRP assays were developed. The Sensitive assay is capable of measuring CRP concentrations as low as lmg/l for use as a potential cardiac marker test. The Normal assay can measure concentrations from 5-400mg/l for establishing levels of inflammation. Both assays developed are latex particle enhanced immunoturbidimetric assays designed for use on …

Dna Multiplex Hybridization On Microarrays And Thermodynamic Stability In Solution: A Direct Comparison, Daniel J. Fish, M. Todd Horne, Greg P. Brewood, Jim P. Goodarzi, Saba Alemayehu, Ashwini Bhandiwad, Robert P. Searles, Albert S. Benight

Chemistry Faculty Publications and Presentations

Hybridization intensities of 30 distinct short duplex DNAs measured on spotted microarrays, were directly compared with thermodynamic stabilities measured in solution. DNA sequences were designed to promote formation of perfect match, or hybrid duplexes containing tandem mismatches. Thermodynamic parameters DeltaH degrees , DeltaS degrees and DeltaG degrees of melting transitions in solution were evaluated directly using differential scanning calorimetry. Quantitative comparison with results from 63 multiplex microarray hybridization experiments provided a linear relationship for perfect match and most mismatch duplexes. Examination of outliers suggests that both duplex length and relative position of tandem mismatches could be important factors contributing to …

Pathways Of Anaerobic Carbon Cycling Across An Ombrotrophic–Minerotrophic Peatland Gradient, Jason K. Keller, Scott D. Bridgham

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Peatland soils represent globally significant stores of carbon, and understanding carbon cycling pathways in these ecosystems has important implications for global climate change. We measured aceticlastic and autotrophic methanogenesis, sulfate reduction, denitrification, and iron reduction in a bog, an intermediate fen, and a rich fen in the Upper Peninsula of Michigan for one growing season. In 3-d anaerobic incubations of slurried peat, denitrification and iron reduction were minor components of anaerobic carbon mineralization. Experiments using 14C-labeled methanogenic substrates showed that methanogenesis in these peatlands was primarily through the aceticlastic pathway, except early in the growing season in more ombrotrophic peatlands, …

Isolation, Characterization, And Degradation Of Bakuchiol From Psoralidium Tenuiflorum, Pei-Jan Hsu

Theses, Dissertations and Culminating Projects

Bioactivity guided fractionation of the EtOAc extract from Psoralidium tenuiflorum afforded the known compound bakuchiol as a racemic mixture. This compound was purified by liquid-liquid partitions and chromatographic techniques followed by characterization with ]H NMR, 13C NMR, and GCMS which agreed with previous literature. Previously, bakuchiol was reported from Psoralea corylirolia and Posoralea glandulosa in nature which are from the same family as P. tenuiflorum. This compound exhibited Staphylococcus epidermidis cytotoxicity.

Two Dimensional NMR (HHCOSY and HETCOR) of bakuchiol indicated a disagreement with the previously described NMR structural assignment; a reassignment is described herein.

Long-term storage followed by attempted reisolation …

The Ksga Methyltransferase: Characterization Of A Universally Conserved Protein Involved In Robosome Biogenesis, Heather Colleen O'Farrell

Theses and Dissertations

The KsgA enzymes comprise an ancient family of methyltransferases that are intimately involved in ribosome biogenesis. Ribosome biogenesis is a complicated process, involving numerous cleavage, base modification and assembly steps. All ribosomes share the same general architecture, with small and large subunits made up of roughly similar rRNA species and a variety of ribosomal proteins. However, the fundamental assembly process differs significantly between eukaryotes and eubacteria, not only in distribution and mechanism of modifications but also in organization of assembly steps. Despite these differences, members of the KsgA/Dim1 methyltransferase family and their resultant modification of small-subunit rRNA are found throughout …