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The Mechanisms of Human Glutathione Synthetase and Related Non-Enyzmatic Catalysis

Description: Human glutathione synthetase (hGS) is a homodimeric enzymes that catalyzes the second step in the biological synthesis of glutathione, a critical cellular antioxidant. The enzyme exhibits negative cooperativity towards the γ-glutamylcysteine (γ-GC) substrate. In this type of allosteric regulation, the binding of γ-GC at one active site significantly reduces substrate affinity at a second active site over 40 Å away. The presented work explores protein-protein interactions, substrate binding, and… more
Date: May 2015
Creator: Ingle, Brandall L.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Genome sequencing reveals complex secondary metabolome in themarine actinomycete Salinispora tropica

Description: Recent fermentation studies have identified actinomycetes ofthe marine-dwelling genus Salinispora as prolific natural productproducers. To further evaluate their biosynthetic potential, we analyzedall identifiable secondary natural product gene clusters from therecently sequenced 5,184,724 bp S. tropica CNB-440 circular genome. Ouranalysis shows that biosynthetic potential meets or exceeds that shown byprevious Streptomyces genome sequences as well as other naturalproduct-producing actinomycete… more
Date: May 1, 2007
Creator: Udwary, Daniel W.; Zeigler, Lisa; Asolkar, Ratnakar; Singan,Vasanth; Lapidus, Alla; Fenical, William et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

ISOLEUCYL-tRNA SYNTHETASE OF E. coli B. A RAPID KINETIC INVESTIGATION OF THE L-ISOLEUCINE ACTIVATING REACTION

Description: We have investigated the preequilibrium kinetics of the L-isoleucine activation reaction catalyzed by Ile-tRNA synthetase in the presence of a fluorescent reporter group, 2-p-toluidinylnaphthalene-6-sulfonate, using the stopped-flow technique. It is found that of all the reactants involved, L-isoleucine binds slowest to the enzyme, apparently in a two-step process. The kinetics of the reaction are invariant in the presence of co-reactants, whereas the kinetics for ATP are drastically changed in… more
Date: May 1, 1972
Creator: Holler, E. & Calvin, Melvin
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Computational Investigation of DNA Repair Enzymes: Determination and Characterization of Cancer Biomarkers and Structural Features

Description: Genomic integrity is important for living cells' correct functioning and propagation. Deoxyribonucleic acid as a molecule is a subject to chemical reactions with agents that can come from environment as well as from internal metabolism processes. These reactions can induce damage to DNA and thus compromise the genetic information, and result in disease and death of an organism. To mitigate the damage to DNA, cells have evolved to have multiple DNA repair pathways. Presented here is a computat… more
Date: May 2018
Creator: Silvestrov, Pavel
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Defining interactions between DNA-PK and ligase IV/XRCC4

Description: Non-homologous end joining (NHEJ) is a major pathway for the repair of DNA double-strand breaks in mammalian cells. DNA-dependent protein kinase (DNA-PK), ligase IV, and XRCC4 are all critical components of the NHEJ repair pathway. DNA-PK is composed of a heterodimeric DNA-binding component, Ku, and a large catalytic subunit, DNA-PKcs. Ligase IV and XRCC4 associate to form a multimeric complex that is also essential for NHEJ. DNA-PK and ligase IV/XRCC4 interact at DNA termini which results in s… more
Date: April 10, 2001
Creator: Hsu, Hsin-Ling; Yannone, Steven M. & Chen, David J.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Laue diffraction protein crystallography at the National Synchrotron Light Source

Description: A new facility for the study of protein crystal structure using Laue diffraction has been established at the X26 beam line of the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory. The characteristics of the beam line and diffraction apparatus are described. Selected results of some of the initial experiments are discussed briefly by beam line users to illustrate the scope of the experimental program. Because the Laue method permits the recording of large data sets in a… more
Date: December 31, 1992
Creator: Getzoff, E. D.; McRee, D.; Jones, K. W.; Spanne, P.; Sweet, R. M.; Moffat, K. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

The importance of cytosolic glutamine synthetase in nitrogen assimilation and recycling

Description: Glutamine synthetase assimilates ammonium into amino acids, thus it is a key enzyme for nitrogen metabolism. The cytosolic isoenzymes of glutamine synthetase assimilate ammonium derived from primary nitrogen uptake and from various internal nitrogen recycling pathways. In this way, cytosolic glutamine synthetase is crucial for the remobilization of protein-derived nitrogen. Cytosolic glutamine synthetase is encoded by a small family of genes that are well conserved across plant species. Members… more
Date: July 2, 2009
Creator: Bernard, S. M. & Habash, D. Z.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Distinct kinetics of human DNA ligases I, IIIalpha, IIIbeta, and IV reveal direct DNA sensing ability and differential physiological functions in DNA repair

Description: The three human LIG genes encode polypeptides that catalyze phosphodiester bond formation during DNA replication, recombination and repair. While numerous studies have identified protein partners of the human DNA ligases (hLigs), there has been little characterization of the catalytic properties of these enzymes. In this study, we developed and optimized a fluorescence-based DNA ligation assay to characterize the activities of purified hLigs. Although hLigI joins DNA nicks, it has no detectable… more
Date: May 11, 2009
Creator: Chen, Xi; Ballin, Jeff D.; Della-Maria, Julie; Tsai, Miaw-Sheue; White, Elizabeth J.; Tomkinson, Alan E. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Tissue-specific changes of glutamine synthetase activity in oats after rhizosphere infestation by Pseudomonas syringae pv. tabaci. Final report

Description: Oats (Avena sativa L. lodi) tolerant of rhizosphere infestation by Pseudomonas syringae pv. tabaci when challenged by the pathogen experience tissue-specific alterations of ammonia assimilatory capabilities. Altered ammonia assimilatory potentials between root and leaf tissue result from selective inactivation of glutamine synthetase (GS) by the toxin Tabtoxinine-B-lactam (TBL). Root GS is sensitive and leaf GSs are resistant to TBL inactivation. With prolonged challenge by the pathogen root GS… more
Date: May 15, 1996
Creator: Knight, T.J.; Temple, S. & Sengupta-Gopalan, C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Proteomic Analysis of Calcium- and Phosphorylation-dependentCalmodulin Complexes in Mammalian Cells

Description: Protein conformational changes due to cofactor binding (e.g. metal ions, heme) and/or posttranslational modifications (e.g. phosphorylation) modulate dynamic protein complexes. Calmodulin (CaM) plays an essential role in regulating calcium (Ca{sup 2+}) signaling and homeostasis. No systematic approach on the identification of phosphorylation-dependent Ca{sup 2+}/CaM binding proteins has been published. Herein, we report a proteome-wide study of phosphorylation-dependent CaM binding proteins fro… more
Date: May 26, 2006
Creator: Jang, Deok-Jin & Wang, Daojing
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Enzyme catalysts for a biotechnology-based chemical industry. Quarterly progress report, April 1--June 28, 1996

Description: The goal of this research is to engineer enzymes to be efficient and economically attractive catalysts for the chemical industry. The author is attempted to demonstrate generally-applicable approaches to enzyme improvement as well as develop specific catalysts for potential industrial application. The paper describes the progress in two projects: (a) Random mutagenesis of pNB esterase: Improved activity and stability; and (2) Subtilisin mutants exhibiting improved ligase activity in organic sol… more
Date: July 22, 1996
Creator: Arnold, F.H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

[Conversion of acetic acid to methane by thermophiles]. Progress report, May 15, 1989--May 14, 1993

Description: The primary goal of this project is to obtain a better understanding of thermophilic microorganisms which convert acetic acid to CH{sub 4}. The previous funding period represents a departure from earlier research in this laboratory, which was more physiological and ecological. The present work is centered on the biochemistry of the thermophile Methanothrix sp. strain CALS-1. this organism presents a unique opportunity, with its purity and relatively rapid growth, to do comparative biochemical s… more
Date: June 1, 1993
Creator: Zinder, S. H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Biochemistry and genetics of autotrophy in Methanococcus

Description: The project investigated fundamental aspects of carbon metabolism and genetics in the methane-producing archaeon Methanococcus maripaludis. The project yielded 23 peer-reviewed publications and five reviews from 1997-2007. PDFs of the peer-reviewed publications are included in the next section. Some papers of special interest are listed below. The pathway of pyruvate biosynthesis was elucidated by a combination of biochemical and physiological studies. This work characterized the very oxygen se… more
Date: March 31, 2009
Creator: Whitman, William B.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Final technical report. A sodium-cycle based organism with improved membrane resistance aimed at increasing the efficiency of energy biotransformations

Description: The aim of the project was to express in E. coli components that would allow a formation of oxidative phosphorylation based on a sodium cycle. This would improve the resistance of cells to organic solvents, detergents and other toxins. The author cloned and expressed the nqr operon from H. influenzae in E. coli. Experiments with membrane vesicles indicated the presence of the functional recombinant sodium pumping NADH dehydrogenase. A gene for a hybrid E. coli/P.modestum ATPase was constructed … more
Date: June 1, 2001
Creator: Lewis, Kim
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Integrated genomic and transcriptomic analysis reveals mycoparasitism as the ancestoral life style of Trichoderma

Description: Mycoparasitism, a lifestyle where one fungus is parasitic on another fungus has special relevance when the prey is a plant pathogen, providing a strategy for biological control of pests for plant protection. Probably, the most studied biocontrol agents are species of the genus Hypocrea/Trichoderma.
Date: April 29, 2011
Creator: Kubicek, Christian P.; Herrera-Estrella, Alfredo; Seidl, Verena; Le Crom, Stéphane; Martinez, Diego A.; Druzhinina, Irina S. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Biomolecular Assembly of Gold Nanocrystals

Description: Over the past ten years, methods have been developed to construct discrete nanostructures using nanocrystals and biomolecules. While these frequently consist of gold nanocrystals and DNA, semiconductor nanocrystals as well as antibodies and enzymes have also been used. One example of discrete nanostructures is dimers of gold nanocrystals linked together with complementary DNA. This type of nanostructure is also known as a nanocrystal molecule. Discrete nanostructures of this kind have a number … more
Date: May 20, 2005
Creator: Micheel, Christine Marya
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries Government Documents Department
open access

ISOLEUCYL-tRNA-SYNTHETASE A FLUORESCENCE STUDY OP THE BINDINGPROPERTIES OF THE SYNTHETASE FROM ESCHERICHIA COLI

Description: Fluorescence properties of purified isoleucyl-tRNA-synthetase isolated from E. coli B have been studied. No changes in the quantum yield, energy or polarization of the emission were detected in the presence (either individually or in combinations) of the substrates and cofactors required for activation of L-isoleucine. In 2.5 M urea enzyme activity and intrinsic fluorescence intensity (at 340 nm) each decrease with time, showing similar kinetics and rate constants. The rate of this decay is red… more
Date: November 1, 1970
Creator: Penzer, Geoffrey R.; Bennett, Edward L. & Calvin, Melvin.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Early steps in protein synthesis and their regulation: a background study related to the biological effects of radiation. Progress report, July 1, 1975--June 30, 1976

Description: This is a continuing study of protein synthesis, involving a search for the role of Ap/sub 4/A and other unusual nucleotides in growth regulation; studies of the mechanism of action of aminoacyl-tRNA ligases and the effect thereof on protein synthesis; a search for new regulators of the translation step, in cell-free systems; and an effort to improve the sensitivity and quantitation of chemical sequencing at the 3'-end of messenger RNA.
Date: March 1, 1976
Creator: Zamecnik, P. C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Genetic Augmentation of Syringyl Lignin in Low-lignin Aspen Trees, Final Report

Description: As a polysaccharide-encrusting component, lignin is critical to cell wall integrity and plant growth but also hinders recovery of cellulose fibers during the wood pulping process. To improve pulping efficiency, it is highly desirable to genetically modify lignin content and/or structure in pulpwood species to maximize pulp yields with minimal energy consumption and environmental impact. This project aimed to genetically augment the syringyl-to-guaiacyl lignin ratio in low-lignin transgenic aspe… more
Date: November 10, 2004
Creator: Tsai, Chung-Jui; Davis, Mark F. & Chiang, Vincent L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Differential gene expression in C4 plants. Research proposal, February 1, 1982-January 31, 1983. [Pea plants]

Description: The topic of this research proposal is slightly different from that originally outlined. Specifically, instead of characterizing the genes encoding the small subunit of RuBP carboxylase and the chlorophyll a/b binding polypeptide from corn, these genes from pea are being characterized. The above polypeptides represent the major products of cytoplasmic protein synthesis in green leaves. CDNA clones encoding the above polypeptides were isolated and characterized. Both of these cDNA clones have no… more
Date: November 1, 1981
Creator: Cashmore, A. R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Laue diffraction protein crystallography at the National Synchrotron Light Source

Description: A new facility for the study of protein crystal structure using Laue diffraction has been established at the X26 beam line of the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory. The characteristics of the beam line and diffraction apparatus are described. Selected results of some of the initial experiments are discussed briefly by beam line users to illustrate the scope of the experimental program. Because the Laue method permits the recording of large data sets in a… more
Date: January 1, 1992
Creator: Getzoff, E. D.; McRee, D. (Scripps Institution of Oceanography, La Jolla, CA (United States)); Jones, K. W.; Spanne, P.; Sweet, R. M. (Brookhaven National Lab., Upton, NY (United States)); Moffat, K. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

[Conversion of acetic acid to methane by thermophiles]

Description: The primary goal of this project is to obtain a better understanding of thermophilic microorganisms which convert acetic acid to CH[sub 4]. The previous funding period represents a departure from earlier research in this laboratory, which was more physiological and ecological. The present work is centered on the biochemistry of the thermophile Methanothrix sp. strain CALS-1. this organism presents a unique opportunity, with its purity and relatively rapid growth, to do comparative biochemical s… more
Date: January 1, 1993
Creator: Zinder, S.H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Beneficial consequences of a selective glutamine synthetase inhibitor in oats and legumes

Description: We report on the effects of administering a unique glutamine synthetase inhibitor to cereals and N/sub 2/-fixing legumes. A bacterium (Pseudomonas syringae pv. tabaci) delivers this inhibitor to provide extended treatment periods; we inoculated the root systems of oat and legume plants with pv. tabaci to provide for delivery of this inhibitor to their root or root/nodule systems. Inoculation of legumes is accompanied by increased plant growth, total plant nitrogen, nodulation, and nitrogen fixa… more
Date: January 1, 1988
Creator: Langston-Unkefer, P.J.; Knight, T.J. & Sengupta-Gopalan, C.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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