Biochemistry, Biophysics, and Structural Biology Commons^™

Evolution Of Selenocysteine Decoding And The Key Role Of Selenophosphate Synthetase In The Pathway Of Selenium Utilization, Gustavo Salinas, Héctor Romero, Xue-Ming Xu, Bradley A. Carlson, Dolph L. Hatfield, Vadim N. Gladyshev

Vadim Gladyshev Publications

The complete sequencing of genomes and the development of in silico methods for identification of genes encoding selenocysteine (Sec)-containing proteins have greatly contributed to shape our view on the evolution of selenium utilization in nature. Current evidence is consistent with the idea that Sec decoding is a late addition to the genetic code and it evolved once, before the separation of archaeal, bacterial and eukaryal domains. Many organisms have lost the Sec decoding trait, but recent evidence has shown that the loss is not irreversible. The distribution of organisms that use UGA as a Sec codon suggests that Sec decoding …

Selenoproteins In Parasites, Gustavo Salinas, Alexei V. Lobanov, Vadim N. Gladyshev

Vadim Gladyshev Publications

Parasites, which cause an enormous burden in the population of the third world, are a diverse group of organisms, many of which are sensitive to oxidative stress imposed by their hosts. In recent years, several selenoprotein families, some with antioxidant properties, have been described and characterized in metazoan parasites. Glutathione peroxidase and thioredoxin glutathione reductase (TGR) appear to be essential selenoproteins in flatworms (phylum Platyhelminthes). TGR is the single enzyme that provides reducing equivalents to both thioredoxin and glutathione pathways, in contrast to hosts, which evolve parallel pathways. In roundworms (phylum Nematoda), selenoproteins have recently been described, revealing …

The 15-Kda Selenoprotein (Sep15): Functional Analysis And Role In Cancer, Vyacheslav M. Labunskyy, Vadim N. Gladyshev, Dolph L. Hatfield

Vadim Gladyshev Publications

The 15-kDa selenoprotein (Sep15) was identified several years ago as a protein of unknown function. In recent years, several lines of evidence implicated Sepl5 in the effect of dietary selenium in cancer prevention. These lines of evidence include: 1) protein expression patterns in normal and malignant cells; 2) identification of polymorphic sites that regulate Sep15 levels and differentially respond to selenium supplementation; 3) location of the Sep15 gene in the human genome; and 4) correlation between Sep15 haplotype and susceptibility to cancer. Functional analyses revealed a specific interaction between Sep15 and a protein folding sensor in the endoplasmic reticulum of …

Mammalian And Other Eukaryotic Selenocysteine Trnas, Bradley A. Carlson, Xue-Ming Xu, Rajeev Shrimali, Aniruddha Sengupta, Min-Hyuk Yoo, Robert Irons, Nianxin Zhong, Dolph L. Hatfield, Byeong Jae Lee, Alexei V. Lobanov, Vadim N. Gladyshev

Vadim Gladyshev Publications

Selenocysteine (Sec) tRNA occupies a prominent position in the expression of selenoproteins as it is essential for their synthesis and it provides the means by which selenium is co-translationally inserted into protein as the amino acid, Sec. Thus, Sec tRNA is regarded as the principle constituent in selenoprotein synthesis. Many features unique to this tRNA have been characterized over the years in mammals and other eukaryotes. In the last five years, the major advances have been in an elucidation of the different roles that the two major Sec tRNA isoforms play in selenoprotein biosynthesis and in Sec biosynthesis. One isoform …

The Mechanism Of Assembly Of The G-Protein Beta Gamma Subunit Dimer By Ck2 Phosphorylated Phosducin-Like Protein And The Chaperonin Containing Tcp-1, Christine M. Baker

Theses and Dissertations

Phosducin-like protein (PhLP) binds G-protein beta gamma subunits and is thought to assist in assembly of the G-protein beta gamma dimer. Phosphorylation of PhLP at serine residues 18-20 by the casein kinase 2 (CK2) appears to play an essential role in this process. PhLP has also been shown to interact with the chaperonin containing TCP-1 (CCT) atop its apical domain, not entering the substrate folding cavity. However, the physiological role of the PhLP-CCT interaction in G-protein beta gamma dimer formation remains unclear. This study addresses the mechanism of G-protein beta gamma assembly by exploring the specific roles of CCT and …

Fabrication Of Polymeric Microfluidic Devices For Protein Analysis, Jikun Liu

Theses and Dissertations

2-Bromoisobutyryl bromide was immobilized on poly(methyl methacrylate) (PMMA) substrates activated using an oxygen plasma. Atom-transfer radical polymerization was then performed to graft poly(ethylene glycol) (PEG) on the PMMA surface. PMMA micro capillary electrophoresis (µCE) devices made with the covalently modified surfaces exhibited substantially reduced electroosmotic flow and nonspecific adsorption of proteins. Both column efficiency and migration time reproducibility were one order of magnitude better with derivatized PMMA µCE devices compared to untreated versions. Fast, reproducible, and efficient separations of proteins and peptides were demonstrated using the PEG-grafted PMMA µCE chips. All analyses were completed in less than 60 seconds, and …

(Review) Green Fluorescent Proteins, Marc Zimmer

Chemistry Faculty Publications

Reviews the book:Green Fluorescent Protein: Properties, Applications, and Protocols. Second Edition. Methods of Biochemical Analysis, Volume 47. Edited by Martin Chalfie and Steven R Kain.Green Fluorescent Protein: Properties, Applications, and Protocols. Second Edition. Methods of Biochemical Analysis, Volume 47. Edited by Martin Chalfie and Steven R Kain. Hoboken (New Jersey): Wiley-Interscience. $89.95. xv + 443 p + 24 pl; ill.; index. ISBN: 0–471–73682–1. 2006.

Hyperhomocysteinemia And Coronary Artery Disease In Pakistan, M Perwaiz Iqbal

Department of Biological & Biomedical Sciences

The relative risk of developing coronary artery disease (CAD) in Pakistani men is highest in early ages. Majority of those suffering from CAD belong to the lower middle socioeconomic stratum of the society. Mild hyperhomocysteinemia (concentration of plasma homocysteine between 15-25 micromol/l) is very commonly seen in Pakistani patients with acute myocardial infarction (AMI) as well as in normal healthy subjects. There appears to be a lack of association between hyperhomocysteinemia and CAD in Pakistani population. There is also no evidence of association of methylenetetrahydrofolate reductase 677C>T mutation with CAD in this population. High prevalence of deficiency of folate …

Membrane Organization And Multimeric Interactions Of The Aer Receptor In E. Coli, Divya Dashrathkumar Amin

Loma Linda University Electronic Theses, Dissertations & Projects

Escherichia coli swims toward niches ideal for generating maximum energy by monitoring the environment with the aerotaxis sensor, Aer. This receptor has an N-terminal PAS domain, which is a sensor module present in a variety of proteins from all kingdoms of life (including humans). To date, the mechanism of signaling from a PAS sensor domain to a single signaling receiver domain has not been resolved. In Aer, the PAS sensor is separated from the signaling region by a membrane anchor. Most "transmembrane prediction" programs forecast a single membrane span for this membrane anchor, but such a topology is inconsistent our …

Desulfovibrio Desulfuricans G20 Tetraheme Cytochrome Structure At 1.5 A˚ And Cytochrome Interaction With Metal Complexes, Mrunalini Pattarkine, J J. Tanner, C A. Bottoms, Y H. Lee, Judy D. Wall

Faculty Works

The structure of the type I tetraheme cytochrome c3 from Desulfovibrio desulfuricans G20 was determined to 1.5 A˚ by X-ray crystallography. In addition to the oxidized form, the structure of the molybdate-bound form of the protein was determined from oxidized crystals soaked in sodium molybdate. Only small structural shifts were obtained with metal binding, consistent with the remarkable structural stability of this protein. In vitro experiments with pure cytochrome showed that molybdate could oxidize the reduced cytochrome, although not as rapidly as U(VI) present as uranyl acetate. Alterations in the overall conformation and thermostability of the metal-oxidized protein were investigated …

Recruitment Of Bad By The Chlamydia Trachomatis Vacuole Correlates With Host-Cell Survival, Philippe Verbeke, Lynn Welter-Stahl, S. Ying, J. Hansen, Georg Hacker, Toni Darville, David M. Ojcius

All Dugoni School of Dentistry Faculty Articles

Chlamydiae replicate intracellularly in a vacuole called an inclusion. Chlamydial-infected host cells are protected from mitochondrion-dependent apoptosis, partly due to degradation of BH3-only proteins. The host-cell adapter protein 14-3-3β can interact with host-cell apoptotic signaling pathways in a phosphorylation-dependent manner. In Chlamydia trachomatis-infected cells, 14-3-3β co-localizes to the inclusion via direct interaction with a C. trachomatis-encoded inclusion membrane protein. We therefore explored the possibility that the phosphatidylinositol-3 kinase (PI3K) pathway may contribute to resistance of infected cells to apoptosis. We found that inhibition of PI3K renders C. trachomatis-infected cells sensitive to staurosporine-induced apoptosis, which is accompanied by mitochondrial cytochrome c …

Thioredoxin Reductase 1 Deficiency Reverses Tumor Phenotype And Tumorigenicity Of Lung Carcinoma Cells, Min-Hyuk Yoo, Xue-Ming Xu, Bradley A. Carlson, Vadim N. Gladyshev, Dolph L. Hatfield

Vadim Gladyshev Publications

Dietary selenium has potent cancer prevention activity. Both low molecular weight selenocompounds and selenoproteins are implicated in this effect. Thioredoxin reductase 1 (TR1) is one of the major antioxidant and redox regulators in mammals that supports p53 function and other tumor suppressor activities. However, this selenium-containing oxidoreductase is also overexpressed in many malignant cells and has been proposed as a target for cancer therapy. To further assess the role of TR1 in the malignancy process, we used RNA interference technology to decrease its expression in mouse lung carcinoma (LLC1) cells. Stable transfection of LLC1 cells with a small interfering RNA …

Cloning And Overexpression Of Imp/Osta, An Essential Escherichia Coli Outer Membrane Protein With A Possible Role In Lipid Transport, Leslie Lekatz

Honors Capstones

Capstone submitted as a graduation requirement for the BSU Honors Program.

In Vitro Expression And Purification Of Class I Mhc Molecules, Loi Cheng

Honors Scholar Theses

The major histocompatibility complex (MHC) is a gene family responsible for many critical functions of the immune system in most vertebrates. The MHC consists of three classes differentiated by their structure and function, and MHC class I encodes antigen binding proteins as well as chaperone and accessory proteins such as tapasin. The purpose of this project is to reconstitute several human MHC class I molecules in their peptide-filled and peptide-deficient forms, and to purify these proteins for biochemical study. The expressed proteins include wild type and mutant variants of the fusion protein human leukocyte antigen HLA-B*0801-fos, and human beta-2-microglobulin (β2m). …

Activation In Neural Networks Controlling Ingestive Behaviors: What Does It Mean, And How Do We Map And Measure It?, Alan Watts, Arshad Khan, Graciela Sanchez-Watts, Dawna Salter, Christina Neuner

Selected Works Temporary Series

No abstract provided.

Activation In Neural Networks Controlling Ingestive Behaviors: What Does It Mean, And How Do We Map And Measure It?, Watts, Arshad Khan, Graciela Sanchez-Watts, Dawna Salter, Christina Neuner

Departmental Papers (Biology)

No abstract provided.

The Response Of A Biocompatible Liquid Crystal To Ions And Chemistry On Nanostructured Surfaces, Anny Huang

Renée Crown University Honors Thesis Projects - All

Traditional lyotropic liquid crystals are composed of amphiphilic molecules forming assemblies in water. Disodium cromoglycate (cromolyn or DSCG) – an antiasthmatic drug – is a novel and unusual lyotropic liquid crystal because it is not amphiphilic, and yet, it exhibits large birefringence (shininess) when dissolved in water forming lyotropic liquid crystal. In the work, DSCG liquid crystal is doped with different types of salt such as sodium chloride and sodium perchlorate, and the response in the changes of birefringence and liquid crystal transition temperature is studied. We find that addition of certain type of salts enhance the propensity of formation …

Mechanisms Imposing The Vbeta Bias Of V14a Natural Killer T Cells And Consequences For Microbial Glycolipid Recognition, Paul B. Savage, Dasten G. Wei, Shane A. Curran, Luc Teyton, Albert Bendelac

Faculty Publications

Mouse and human natural killer T (NKT) cells recognize a restricted set of glycosphingolipids presented by CD1d molecules, including self iGb3 and microbial alpha-glycuronosylceramides. The importance of the canonical Valpha 14-Jalpha18 TCR alphachain for antigen recognition by NKT cells is well recognized, but the mechanisms underlying the Vbeta8, Vbeta7, and Vbeta2 bias in mouse have not been explored. To study the influences of thymic selection and the constraints of pairing with Valpha 14-Jalpha 18, we have created a population of mature T cells expressing Valpha 14-Jalpha 18 TCRalpha chain in CD1d-deficient mice and studied its recognition properties in vitro and …

Evaluation Of Toxicity Following Electrically Mediated Interleukin-12 Gene Delivery In A B16 Mouse Melanoma Model, Loree Heller, Kathleen Merkler, Jeffrey Westover, Yolmari Cruz, Domenico Coppola, Kaaron Benson, Adil Daud, Richard Heller

Bioelectrics Publications

PURPOSE: Interleukin-12 (IL-12) has potential as an immunotherapeutic agent for the treatment of cancer but is unfortunately associated with toxicity. Delivery of a plasmid encoding IL-12 with electroporation induces an antitumor effect in the B16 mouse melanoma model without serious side effects. To translate this observation to the clinic, an evaluation of toxicity was done in the mouse model.

EXPERIMENTAL DESIGN: Weight change, tumor response, blood chemistry and hematology values, and serum IL-12 levels were evaluated. Multiple tissues were analyzed histopathologically.

RESULTS: A pronounced reduction in tumor volume, including a large percentage of complete regressions, was observed after electrically mediated …

Ethanol Production From Grain, Department Of Agriculture And Food, Western Australia

All other publications

Two methods are currently used to produce ethanol from grain: wet milling and dry milling. The adjectives ‘wet’ and ‘dry’ describe the method, not the product. The different methods affect both the profitability and logistics. Dry mills produce ethanol, distillers' grain and carbon dioxide (Figure 1). The carbon dioxide is a co-product of the fermentation, and the distillers’ dried grain with solubles (DDGS) is a non-animal based, high protein livestock feed supplement, produced from the distillation and dehydration process. If distillers' grains are not dried, they are referred to as distillers' wet grain (DWG). Wet mill facilities are ‘bio-refineries’ producing …

A Sensitive Subject: Haploinsufficiency Of The Yeast Vma13 Gene In Simple And Compound Heterozygotes, Jason Michael Rizzo

Renée Crown University Honors Thesis Projects - All

Vacuolar-proton translocating-ATPases (V-ATPases) are the membranebound transporters responsible for controlling pH levels in intracellular compartments. The V-ATPase enzyme is a multi-subunit complex consisting of two distinct domains, a cytosolic V1 region and a membrane-bound Vo domain. While the interface between V1 and Vo is not as well understood, studies suggest the possibility of multiple peripheral stalks tethering the complex. In response to glucose deprivation, the V1 and Vo sectors of the enzyme are capable of dissociating into separate, and inactive, domains as a means of regulation. At least 4 V1 subunits (C, H, E, and G) are believed to form …

The Role Of Trailerhitch In Mouse Germ Cell Development, Ashley L. O'Hara

Renée Crown University Honors Thesis Projects - All

During oogenesis in the Drosophila ovary, a 16-cell cyst develops in which one cell grows to become the oocyte. The surrounding nurse cells transport mRNAs, proteins, and organelles to the oocyte during development and must be localized properly within the oocyte. A complex of proteins is responsible for mRNA localization, including the recently discovered protein Trailerhitch. Homologs of Trailerhitch exist in other species including C. elegans, yeast, mice, and humans, but the function is unknown. We are interested in studying the function of Trailerhitch in mouse germ cell development. Mice with a nonfunctional Trailerhitch gene were synthesized using a gene …

Total Synthesis Of Pumiliotoxin 341a, Lydia Choi

Renée Crown University Honors Thesis Projects - All

Pumiliotoxin 341 A differs from all other pumiliotoxins in that its alkylidene side chain has been cyclized to form a pyranose ring, providing another quaternary center in its indolizidine ring. Although the gross structure of this natural product has been determined, the absolute and relative stereochemistry of the tertiary alcohol on C14 is still unknown. As a result, we want to synthesize this alkaloid to prove its stereochemistry and to prepare material for further biological analysis. A rhodium-catalyzed alkyne addition reaction currently being developed in our group is employed as the key reaction in our synthesis of the indolizidine core. …

Isolation Of A Ubiquitous Obligate Thermoacidophilic Archaeon From Deep-Sea Hydrothermal Vents, Anna-Louise Reysenbach, Yitai Liu, Amy B. Banta, Terry J. Beveridge, Julie D. Kirshtein, Stefan Schouten, Margaret K. Tivey, Karen L. Von Damm, Mary A. Voytek

Biology Faculty Publications and Presentations

Deep-sea hydrothermal vents are important in global biogeochemical cycles, providing biological oases at the sea floor that are supported by the thermal and chemical flux from the Earth's interior. As hot, acidic and reduced hydrothermal fluids mix with cold, alkaline and oxygenated sea water, minerals precipitate to form porous sulphide–sulphate deposits. These structures provide microhabitats for a diversity of prokaryotes that exploit the geochemical and physical gradients in this dynamic ecosystem. It has been proposed that fluid pH in the actively venting sulphide structures is generally low (pH < 4.5), yet no extreme thermoacidophile has been isolated from vent deposits. Culture-independent surveys based on ribosomal RNA genes from deep-sea hydrothermal deposits have identified a widespread euryarchaeotal lineage, DHVE2 (deep-sea hydrothermal vent euryarchaeotic 2) Despite the ubiquity and apparent deep-sea endemism of DHVE2, cultivation of this group has been unsuccessful and thus its metabolism remains a mystery. Here we report the isolation and cultivation of a member of the DHVE2 group, which is an obligate thermoacidophilic sulphur- or iron-reducing heterotroph capable of growing from pH 3.3 to 5.8 and between 55 and 75 °C. In addition, we demonstrate that this isolate constitutes up to 15% of the archaeal population, providing evidence that thermoacidophiles may be key players in the sulphur and iron cycling at deep-sea vents.

The Fate Of Iron Released From Heme By Hemeoxygenase-1, Jonathan Mark Gardner

Undergraduate Honors Capstone Projects

A strain of Escherichia coli was genetically modified to co-express human heme oxygenase-1 and ferritin. The E. coli were then grown with varying amounts of hemin to see if the iron released upon degradation of the hemin by heme oxygenase-1 is loaded into ferritin. Following incubation, the ferritin was purified and the amount of iron loaded into ferritin determined. It was found that ferritin purifed from E. coli expressing human heme oxygenase-1 contained more iron than E. coli that did not contain human heme oxygenase-1. It was concluded that some of the iron released upon degradation of hemin by heme …

Biogeochemistry Of Arsenic And Antimony In The North Pacific Ocean, Gregory A. Cutter, Lynda S. Cutter

OES Faculty Publications

The biogeochemical cycles of the metalloid elements arsenic and antimony were examined along a 15,000 km surface water transect and at 9 vertical profile stations in the western North Pacific Ocean as part of the 2002 IOC Contaminant Baseline Survey. Results show that the speciation of dissolved arsenic (As III, As V, and methylated As) was subtly controlled by the arsenate (AsV)/phosphate ratio. An additional fraction of presumed organic arsenic previously reported in coastal waters was also present (~15% of the total As) in oceanic surface waters. Dissolved inorganic antimony displayed mildly scavenged behavior that was confirmed by correlations with …

Defocused Orientation And Position Imaging (Dopi) Of Myosin V, Rolfe G. Petschek

Faculty Scholarship

The centroid of a fluorophore can be determined within 1.5-nm accuracy from its focused image through fluorescence imaging with one-nanometer accuracy (FIONA). If, instead, the sample is moved away from the focus, the point-spread-function depends on both the position and 3D orientation of the fluorophore, which can be calculated by defocused orientation and position imaging (DOPI). DOPI does not always yield position accurately, but it is possible to switch back and forth between focused and defocused imaging, thereby getting the centroid and the orientation with precision. We have measured the 3D orientation and stepping behavior of single bifunctional rhodamine probes …

Erratum: "Hard Sphere Radial Distribution Function Again", Andrij Trokhymchuk, Douglas Henderson, Ivo Nezbeda, Jan Jirsak

Faculty Publications

Some misprints have been found for parameters given by Eqs. 29 and 30 and the relevant equations in the Appendix.

Two New Resorcinarenes: A Pyridine & Acetic Acid Ligand For Metal Coordination And A Deep-Cavity Nitroquinoxaline Resorcinarene, Samantha Sizemore Vernetti

Theses and Dissertations

Functionalizing the upper rim of resorcinarene-based cavitands allows a variety of compounds to be synthesized from a single scaffold. Using the upper-rim moieties as ligands for a variety of transition metal ions further increases the versatility of this class of host compounds. A new resorcinarene-based molecule functionalized with four pyridine and acetic acid ligands has been successfully prepared to explore the properties of metal-assembled complexes. To synthesize this compound, tetra(bromomethyl)cavitand was reacted with N-(2-pyridylmethyl)-N-ethylacetate amine to give ethyl acetate pyridine resorcinarene. Hydrolysis of the ester gave acetic acid pyridine resorcinarene (APRes) in good yield. Complexes with Cu2+, Co2+, and Zn2+ …

Development Of A High Spatial Selectivity Tri-Polar Concentric Ring Electrode For Laplacian Electroencephalography (Leeg) System, Kanthaiah Koka

Doctoral Dissertations

Brain activity generates electrical potentials that are spatio-temporal in nature. Electroencephalography (EEG) is the least costly and most widely used non-invasive technique for diagnosing many brain problems. It has high temporal resolution but lacks high spatial resolution.

The surface Laplacian will enhance the spatial resolution of EEG as it performs the second spatial derivative of the surface potentials. In an attempt to increase the spatial selectivity, researchers introduced a bipolar electrode configuration using a five point finite difference method (FPM) and others applied a quasi-bipolar (tri-polar with two elements shorted) concentric electrode configuration. To further increase the spatial resolution, the …