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Articles 181 - 210 of 251

Full-Text Articles in Biochemistry, Biophysics, and Structural Biology

Role Of Protein Kinase C Isotypes In 1,25-Dihydroxyvitamin D3 Mediated Signal Transduction Through The 1,25d3 Membrane Associated, Rapid Response Steroid Binding Receptors In Chick Intestinal Cells, Sakara Tunsophon May 2010

Role Of Protein Kinase C Isotypes In 1,25-Dihydroxyvitamin D3 Mediated Signal Transduction Through The 1,25d3 Membrane Associated, Rapid Response Steroid Binding Receptors In Chick Intestinal Cells, Sakara Tunsophon

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

It is now accepted that 1,25(OH)2D3 mediates its rapid actions on the control of phosphate and calcium homeostasis through its membrane receptor termed the 1,25D3-MARRS (membrane associated rapid response steroid binding) protein. I determined the various PKC isotypes involved in the rapid regulation of phosphate uptake and calcium extrusion in chick intestinal cells. 1,25(OH)2D3-mediated phosphate uptake was stimulated within 1 min after addition of the hormone. Western blot analyses on isolated intestinal cells treated with steroid hormone resulted in dose-dependent increases in PKC alpha and PKC beta in postnuclear centrifugation fractions, but not in the low speed centrifugation fractions. The …


Development Of Novel Methods And Their Utilization In The Analysis Of The Effect Of The N-Terminus Of Human Protein Arginine Methyltransferase 1 Variant 1 On Enzymatic Activity, Protein-Protein Interactions, And Substrate Specificity, Brenda Bienka Suh-Lailam May 2010

Development Of Novel Methods And Their Utilization In The Analysis Of The Effect Of The N-Terminus Of Human Protein Arginine Methyltransferase 1 Variant 1 On Enzymatic Activity, Protein-Protein Interactions, And Substrate Specificity, Brenda Bienka Suh-Lailam

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Protein arginine methyltransferases (PRMTs) are enzymes that catalyze the methylation of protein arginine residues, resulting in the formation of monomethylarginine, and/or asymmetric or symmetric dimethylarginines. Although understanding of the PRMTs has grown rapidly over the last few years, several challenges still remain in the PRMT field. Here, we describe the development of two techniques that will be very useful in investigating PRMT regulation, small molecule inhibition, oligomerization, protein-protein interaction, and substrate specificity, which will ultimately lead to the advancement of the PRMT field. Studies have shown that having an N-terminal tag can influence enzyme activity and substrate specificity. The first …


An Entrepreneurial Approach To Librarianship, Flora Shrode, Jennifer Duncan, Wendy Holliday Apr 2010

An Entrepreneurial Approach To Librarianship, Flora Shrode, Jennifer Duncan, Wendy Holliday

Library Faculty & Staff Publications

Librarians from Utah State University explain recent efforts to encourage subject librarians to take a more holistic view of their roles. We are shifting from a traditional emphasis primarily on collection development and refocusing on natural connections between collections, instruction, liaison, and reference service. The poster provides background about Utah State University’s situation and explains our approach to analyzing local needs and culture to inform development of a new organizational structure. We describe our vision of subject librarianship, the process by which we assessed librarians’ ideas and goals for performing as subject librarians, and the actions we are taking to …


Human Health Relies On Proper Cellular Communication, Which Starts With Protein Recognition, Zaharah Rossi, Bella Lonardo Jan 2010

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.


Subcutaneous Administration Of Tc007 Reduces Disease Severity In An Animal Model Of Sma, Virginia B. Mattis, Marina Y. Fosso, Cheng-Wei Tom Chang, Christian L. Lorson Nov 2009

Subcutaneous Administration Of Tc007 Reduces Disease Severity In An Animal Model Of Sma, Virginia B. Mattis, Marina Y. Fosso, Cheng-Wei Tom Chang, Christian L. Lorson

Chemistry and Biochemistry Faculty Publications

Background Spinal Muscular Atrophy (SMA) is the leading genetic cause of infantile death. It is caused by the loss of functional Survival Motor Neuron 1 (SMN1). There is a nearly identical copy gene, SMN2, but it is unable to rescue from disease due to an alternative splicing event that excises a necessary exon (exon 7) from the majority of SMN2-derived transcripts. While SMNΔ7 protein has severely reduced functionality, the exon 7 sequences may not be specifically required for all activities. Therefore, aminoglycoside antibiotics previously shown to suppress stop codon recognition and promote translation read-through have been examined to increase the …


Characterization Of The Substrate Specificity And Mechanism Of Protein Arginine Methyltransferase 1, Whitney Lyn Wooderchak May 2009

Characterization Of The Substrate Specificity And Mechanism Of Protein Arginine Methyltransferase 1, Whitney Lyn Wooderchak

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Protein arginine methyltransferases (PRMTs) posttranslationally modify protein arginine residues. Type I PRMTs catalyze the formation of monomethylarginine (MMA) and asymmetric dimethylarginine (ADMA) via methyl group transfer from S-adenosyl methionine onto protein arginine residues. Type II PRMTs generate MMA and symmetric dimethylarginine. PRMT-methylation affects many biological processes. Although PRMTs are vital to normal development and function, PRMT-methylation is also linked to cardiovascular disease, stroke, multiple sclerosis, and cancer.

Thus far, nine human PRMT isoforms have been identified with orthologues present in yeast, plants, and fish. PRMT1 predominates, performing an estimated 85% of all protein arginine methylation in vivo. Yet, the substrate …


A Comparative Study Of The Structural Features And Kinetic Properties Of The Mofe And Vfe Proteins From Azotobacter Vinelandii, Miguel Alejandro Pabon Sanclemente May 2009

A Comparative Study Of The Structural Features And Kinetic Properties Of The Mofe And Vfe Proteins From Azotobacter Vinelandii, Miguel Alejandro Pabon Sanclemente

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Biological nitrogen fixation is accomplished in the bacterium Azotobacter vinelandii by means of three metalloenzymes: The molybdenum, vanadium, and iron-only nitrogenase. The knowledge regarding biological nitrogen fixation has come from studies on the Mo-dependent reaction. However, the V- and Fe-only-dependent reduction of nitrogen remains largely unknown.

By using homology modeling techniques, the protein folds that contain the metal cluster active sites for the V- and Fe-only nitrogenases were constructed. The models uncovered similarities and differences existing among the nitrogenases regarding the identity of the amino acid residues lining pivotal structural features for the correct functioning of the proteins. These differences, …


Phase-Transfer Catalyzed Synthesis Of The Soy Isoflavanoid S-Equol, A. W. Butler, A. L. Calvert, Michael A. Christiansen, M. B. Andrus Apr 2009

Phase-Transfer Catalyzed Synthesis Of The Soy Isoflavanoid S-Equol, A. W. Butler, A. L. Calvert, Michael A. Christiansen, M. B. Andrus

Chemistry and Biochemistry Faculty Presentations

S-Equol is an isoflavanoid metabolized from the isoflavone daidzein by intestinal bacteria. Only 30-50 percent of all individuals possess bacteria that produce S-Equol. Recent data supports the compound’s pharmaceutical potential for treating prostate cancer and post-menopausal estrogen deficiency (ref. 1). Because the compound is only minutely available from natural sources, an affordable asymmetric total synthesis would be necessary to generate sufficient quantities for expanded research. Only one asymmetric total synthesis of S-Equol has been reported to date, using a chiral auxiliary to give product in a 10 percent yield over 6 steps (ref. 2). It is our goal to develop …


Synthesis Of Kurasoin B Analogs, J. R. Nielson, Michael A. Christiansen, M. B. Andrus Apr 2009

Synthesis Of Kurasoin B Analogs, J. R. Nielson, Michael A. Christiansen, M. B. Andrus

Chemistry and Biochemistry Faculty Presentations

Kurasoin B (1), isolated in 1996 by Uchida et al, selectively inhibits Farnesyltransferase (FTase), an enzyme responsible for activating human RAS proteins (ref. 1). When RAS proteins are mutated and then activated, they contribute 20 to 30 percent of all human tumors, including those of the pancreas, colon, small intestine, lung, prostate, liver, skin, and thyroid, as well as multiple myeloma and a number of leukemias (ref. 2). Kurasoin B, therefore, has great potential as a cancer drug lead.


Phase-Transfer Catalyzed Asymmetric Synthesis Of S-Naproxen, M. A. Binkley, Michael A. Christiansen, K. H. Harper, M. B. Andrus Jan 2009

Phase-Transfer Catalyzed Asymmetric Synthesis Of S-Naproxen, M. A. Binkley, Michael A. Christiansen, K. H. Harper, M. B. Andrus

Chemistry and Biochemistry Faculty Presentations

This presentation explores a modified approach to Kurasoin B.


Liposomes Recruit Ipac To The Shigella Flexneri Type Iii Secretion Apparatus Needle As A Final Step In Secretion Induction, C. R. Epler, Nicholas E. Dickenson, A. J. Olive, W. L. Picking, W. D. Picking Jan 2009

Liposomes Recruit Ipac To The Shigella Flexneri Type Iii Secretion Apparatus Needle As A Final Step In Secretion Induction, C. R. Epler, Nicholas E. Dickenson, A. J. Olive, W. L. Picking, W. D. Picking

Chemistry and Biochemistry Faculty Publications

Shigella flexneri contact with enterocytes induces a burst of protein secretion via its type III secretion apparatus (TTSA) as an initial step in cellular invasion. We have previously reported that IpaD is positioned at the TTSA needle tip (M. Espina et al., Infect. Immuno. 74:4391-4400, 2006). From this position, IpaD senses small molecules in the environment to control the presentation of IpaB to the needle tip. This step occurs without type III secretion induction or IpaC recruitment to the S. flexneri surface. IpaC is then transported to the S. flexneri surface when target cell lipids are added, and this event …


Synthesis Of 12-Hete Using Asymmetric Phase-Transfer Catalysis, Michael A. Christiansen, M. B. Andrus Jan 2009

Synthesis Of 12-Hete Using Asymmetric Phase-Transfer Catalysis, Michael A. Christiansen, M. B. Andrus

Chemistry and Biochemistry Faculty Presentations

A new method of asymmetric phase-transfer-catalyzed alkylation is described. The synthetic utility of this method is demonstrated with the total syntheses of kurasoin A, kurasoin B, and S-naproxenTM, with current work toward S-equol. This methodology is currently being applied to an improved asymmetric total synthesis of the natural compound 12-S-HETE.


Expression Analysis Of Plant Defense Responses During The Establishment Of Biotrophy And Role Of Abiotic Stress In The Infection Of Dyer’S Woad (Isatis Tinctoria) By Puccinia Thlaspeos, Elizabeth Thomas May 2008

Expression Analysis Of Plant Defense Responses During The Establishment Of Biotrophy And Role Of Abiotic Stress In The Infection Of Dyer’S Woad (Isatis Tinctoria) By Puccinia Thlaspeos, Elizabeth Thomas

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The kinetics and amplitude of the salicylic acid-responsive pathogenesis-related (PR) genes and the cytochrome P450 gene ItCYP79B2 in the compatible interaction between Puccinia thlaspeos and dyer’s woad (Isatis tinctoria) during the first 72 hours of inoculation were examined. Immediately following penetration of the host by the rust pathogen, there was a modest up-regulation of PR genes but a significant down-regulation of ItCYP79B2 expression. During haustoria formation, a significant pathogen-mediated suppression of PR genes was observed with a corresponding up-regulation of ItCYP79B2. This potentially facilitates haustoria formation by P. thlaspeos. After haustoria formation, a more …


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 Jan 2007

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 …


The Fate Of Iron Released From Heme By Hemeoxygenase-1, Jonathan Mark Gardner May 2006

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 …


Role Of Iron In The Mechanism Of Asbestos-Induced Apoptosis In Human Lung And Pleural Target Cells, Aleksander Baldys May 2004

Role Of Iron In The Mechanism Of Asbestos-Induced Apoptosis In Human Lung And Pleural Target Cells, Aleksander Baldys

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Occupational exposure to asbestos has been associated with increased incidence of pulmonary interstitial fibrosis, mesothelioma of the pleura, and bronchogenic carcinoma. Although the mechanism by which asbestos causes cancer remains unknown, iron associated with asbestos is thought to play a role in the pathogenic effects of fibers.

The aim of this research was to examine and compare the asbestos-induced signaling phenomena in relevant human lung and pleural target cells, and to determine the role of iron from asbestos fibers in these events. Exposure of human airway epithelial (A549) cells, human pleural mesothelial (MET5A) cells, and normal human small airway epithelial …


Functional Characterization Of The Nonstructural Protein 2 Of Bluetongue Virus Serotype 17, Gary Christopher Fillmore May 2000

Functional Characterization Of The Nonstructural Protein 2 Of Bluetongue Virus Serotype 17, Gary Christopher Fillmore

Biology

Bluetongue virus (BTV) is an arthropod-borne pathogen that causes bluetongue disease (BD) throughout the world, with economic losses primarily coming from infection of domestic livestock. Although BTV has been well studied at the molecular level since 1969, the mechanism of viral replication has not yet been fully determined. The virus is composed of seven structural and four nonstructural proteins, and the role of each protein has been investigated but has not been conclusively established within the viral life cycle. This study focused on the nonstructural protein NS2 in an attempt to examine its functions as part of the viral replication …


Studies On The Roles Of Atp In Nitrogenase Catalysis, Wei Wu May 2000

Studies On The Roles Of Atp In Nitrogenase Catalysis, Wei Wu

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Nitrogenase is the enzyme that catalyzes the reduction of nitrogen to ammonia in a reaction requiring MgATP hydrolysis. Two component proteins of nitrogenase are the iron protein (Fe protein) and the molybdenum-iron protein (MoFe protein).

Nitrogenase contains two nucleotide binding sites. During catalysis, the Fe protein binds two MgATP first. The conformational changes induced upon MgATP binding allow the Fe protein to associate with the MoFe protein. After the formation of the Fe protein-MoFe protein complex, a single electron is transferred from the Fe protein to the MoFe protein, an event that is coupled to MgATP hydrolysis in the Fe …


Expression, Purification, And Characterization Of Nonstructural Protein 2 (Ns2) Of Bluetongue Virus Serotype 17, Hai Lin May 1998

Expression, Purification, And Characterization Of Nonstructural Protein 2 (Ns2) Of Bluetongue Virus Serotype 17, Hai Lin

Biology

The NS2 protein of bluetongue virus (BTV) serotype 17 (B17) was expressed in large scale as a Glutathione-S-Transferase (GST) fusion protein in E. coli cells. The size of the expressed NS2/GST fusion protein was about 68 kilodaltons (kDa) when analyzed by sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE). This is equal to the sum of the predicted size from the deduced amino acid sequence of the NS2 protein (41 kDa) and the known mass of the GST protein (27 kDa). The NS2/GST fusion protein was purified by absorption to glutathione-conjugated agarose beads (G-beads), and then analyzed on western blots by two …


Studies Of Dictyostelium Discoideum Plasmid Ddp6 And On The Mechanism Of Action Of Rep Proteins From The Ddp2 Plasmid Family, Iman M. Shammat May 1997

Studies Of Dictyostelium Discoideum Plasmid Ddp6 And On The Mechanism Of Action Of Rep Proteins From The Ddp2 Plasmid Family, Iman M. Shammat

Biology

Dictyostelium discoideum plasmid Ddp6 from the wild strain NC47.2 is a 5257 bp nuclear plasmid with a copy number of 200-300 per cell. Analysis of the nucleotide sequence and structural organization of the Ddp6 plasmid has identified it as a new member of the Ddp2 plasmid family. Ddp6 contains a single gene that is homologous to the rep gene of Ddp2. As with Ddp2, a single constitutively expressed transcript of 3.3 kb was detected from the rep gene. The Ddp6 Rep open reading frame of 2.8 kb encodes a protein of 932 amino acids. A set of 10 conserved peptide …


Characterization Of The Tdd-4 Transposable Element From Dictyostelium Discoideum, David J. Wells May 1996

Characterization Of The Tdd-4 Transposable Element From Dictyostelium Discoideum, David J. Wells

Biology

Transposable elements are DNA segments that possess the capability to move to new chromosomal or extrachromosomal locations. Tdd-4 is a newly isolated transposable element from Dictyostelium discoideum that was captured while studying maintenance properties of Dictyostelium plasmids. Approximately 20 copies are present in the D. discoideum AX4 genome. Two classes of elements were identified, which include a 3.8 kilobase full-length version and a 3.4 kilobase deleted version. Restriction fragment length polymorphism analysis demonstrates that Tdd-4 utilizes a cut-and-paste mode of transposition. Sequence analysis reveals that the 145 base pair inverted terminal repeats contain the 5'-TG...CA-3' conserved terminal dinucleotides found in …


Phylogenetic Studies Of The United States Bluetongue Viruses And Characterization Of The Viral Vp4 Protein, I-Jen Huang May 1996

Phylogenetic Studies Of The United States Bluetongue Viruses And Characterization Of The Viral Vp4 Protein, I-Jen Huang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Bluetongue virus (BTV) is transmitted by arthropod vectors and causes bluetongue disease with serious economic loss in many regions of the world. The replication mechanism of bluetongue virus is still not clear. To have a better understanding regarding the viral replication, the function of each individual protein has to be identified. This study used molecular biology techniques to investigate the function of the inner core protein VP4.

The M1 genes of United States bluetongue virus serotypes-2, -10, -11, -13, and -17 were cloned and sequenced. The length of each of the five M1 genes is 1981 nucleotides. The coding region …


Characterization Of An Axial Ligand Substitution In Sperm Whale Myoglobin, Michael J. Chen May 1995

Characterization Of An Axial Ligand Substitution In Sperm Whale Myoglobin, Michael J. Chen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Of central importance to the study of heme proteins are the effects imposed by axial ligand(s) on the heme structure and, therefore, on the overall activity of the protein. In this study, we confirm and extend the spectroscopic characterization of a mutated sperm whale myoglobin in which the proximal Histidine is replaced with a Tyrosine residue (MbH93Y). The MbH93Y, as well as wild-type sperm whale myoglobin and horse erythrocyte catalase (HEC), was purified and characterized by optical absorption and x-ray absorption (XAS) spectroscopies. Optical absorption spectra of HEC and the metmyoglobin, cyanometmyoglobin, reduced, oxy, and carbon-monoxy forms of both sperm …


Extended X-Ray Absorption Fine Structure And Redox Potential Studies Of Heme-Substituted Horseradish Peroxidase And Myoglobin, Bing He May 1995

Extended X-Ray Absorption Fine Structure And Redox Potential Studies Of Heme-Substituted Horseradish Peroxidase And Myoglobin, Bing He

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Heme-substituted horseradish peroxidases and myoglobins were reconstituted from the apoenzyme using mesoheme and diacetyldeuteroheme. X-ray absorption spectroscopy was used to determine the dimensions of the active sites of these heme-substituted proteins, and were compared with those of the proto-hemeproteins. The change in the active-site structure corresponded with the electron withdrawing and donating effects of the different side chains. The oxidation-reduction potentials of Fe4+/Fe3+ couples of the heme-substituted proteins were measured at pH 7 with K2IrCl6. The oxidation-reduction potential sequence for compound I/compound II was diacetyldeutero- > proto- > meso- in horseradish peroxidase. The oxidation-reduction potential …


Mobilization Of Iron Enhances The Iron-Dependent Biochemical Reactivity Of Asbestos In Vitro And Contributes To The Cytotoxicity Of Asbestos In Cultured Cells, Loren Glen Lund May 1992

Mobilization Of Iron Enhances The Iron-Dependent Biochemical Reactivity Of Asbestos In Vitro And Contributes To The Cytotoxicity Of Asbestos In Cultured Cells, Loren Glen Lund

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Asbestos related research began approximately 60 years ago, yet, the mechanism(s) by which asbestos exerts its biological effects is not well understood. The hypothesis upon which this dissertation is based is that mobilization of iron from asbestos enhances the iron-dependent biochemical reactivity of asbestos in vitro and contributes to asbestos-dependent cytotoxicity. The specific aims for this hypothesis were, 1) to determine whether iron was responsible for the biochemical reactivity of asbestos in vitro and asbestos-induced cytotoxicity in cultured cells, and 2) to determine whether mobilization of iron from asbestos enhanced the reactions catalyzed by asbestos in vitro and contributes to …


Heterologous Expression And Characterization Of Three Active Recombinant Fungal Peroxidases From Phanerochaete Chrysosporium Using Baculovirus, Todd M. Johnson May 1991

Heterologous Expression And Characterization Of Three Active Recombinant Fungal Peroxidases From Phanerochaete Chrysosporium Using Baculovirus, Todd M. Johnson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In a collaborative effort with Dr. Steven D. Aust's group at Utah State University, this research is the first to describe the heterologous expression of active peroxidases from the filamentous fungus Panerochaete chrysosporium. The cDNA clones λML-1, λML-6, λML-5 and λMP-1, which had been tentatively identified as fungal peroxidase clones, were subcloned into baculovirus transfer vectors and recombinant Autographa californica nuclear polyhedrosis viruses were constructed which contained copies of these potential peroxidase genes. The recombinant baculovirus clones were used to infect insect cells for the heterologous production of active recombinant enzymes. Three recombinant lignin peroxidases (H2, H6 and H8) …


Energetic Requirements For Bacterial Protein Export, John Andrew Corbett May 1990

Energetic Requirements For Bacterial Protein Export, John Andrew Corbett

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Bacterial protein export involves the translocation of precursor proteins across the inner cytoplasmic membrane. Over 100 proteins are exported from Escherichia coli. This study showed that energy in the form of ATP and membrane gradient energy is essential for the export of leucine specific binding protein and β-lactamase precursors. Ionophores or combinations of ionophores (SF6847, valinomycin/nigericin and valinomycin/monensin) which dissipate protonmotive force inhibit protein export. Valinomycin alone also inhibits export, but not as well as reagents which dissipate protonmotive force. Nigericin or monensin alone slightly stimulate protein export. These results suggest that the transmembrane electrical potential (∆Ψ) is the …


A Study Of Denitrosation Of N-Nitroso Compounds By Irradiation With Long-Wavelength Uv Light, Zhenyu J. Wang May 1989

A Study Of Denitrosation Of N-Nitroso Compounds By Irradiation With Long-Wavelength Uv Light, Zhenyu J. Wang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

N-Nitrosamines and N-nitrosamides have been reported to be mutagenic. N-Nitrosamides are direct mutagens that need no activation to be mutagenic, whereas N-nitrosamines need to be enzymatically activated to exert their mutagenicity. Oxidative demethylation of nitrosamines is a commonly accepted activation mechanism. Another pathway of nitroso compounds, denitrosation, has recently been proposed. The mechanism of denitrosation, however, is still unknown.

The purpose of this study was to use a photo -reaction model to explore the possible denitrosation mechanism of N-nitroso compounds. An N-nitrosamine, N-nitrosomorpholi ne (NMOR), and an N-nitrosamide, N-methyl-N'-nitrosoguanidine (MMNG), were irradiated with long-wavelength UV light in the presence of …


Peptide Mapping Analysis Of Vp5 And Vp7 From Five Bluetongue Viruses Isolated In The United States, Yi-Yuan Yang May 1989

Peptide Mapping Analysis Of Vp5 And Vp7 From Five Bluetongue Viruses Isolated In The United States, Yi-Yuan Yang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

BTV-2, 10, 11, 13 and 17 were purified by three discontinuous sucrose gradients. Viral proteins were separated from the genomic double-stranded RNA using a newly developed KCI-SDS (sodium dodecyl sulfate) precipitation method. Cyanogen bromide (CNBr) peptide mapping of VP5 and VP7 from bluetongue virus (BTV) serotypes 2, 10, 11, 13 and 17 was then done using silver-stained SDS-polyacrylamide gels. The antigenic epitopes of VP5 and VP7 digested with CNBr were also investigated with polyclonal antibodies produced against KCl-SCS precipitated BTV-13 viral proteins. The peptide maps and the antigenic epitopes of VP7 were similar among the five American serotypes with very …


The Involvement And Relationship Of Ferritin And Ceruloplasmin In Oxygen Radical Toxicities, David Wilson Reif May 1989

The Involvement And Relationship Of Ferritin And Ceruloplasmin In Oxygen Radical Toxicities, David Wilson Reif

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The intent of this dissertation is to demonstrate that ferritin iron may be involved in alloxan, diquat, and radiation-dependent damage and that ceruloplasmin may afford protection by limiting the availability of ferritin iron. Initial studies demonstrated that the alloxan radical formed by glutathione-dependent reduction of alloxan reductively mobilized ferritin iron and the released iron catalyzed lipid peroxidation. SOD and catalase were without effect, whereas ceruloplasmin effectively inhibited both iron release and lipid peroxidation. Using 137Cs gamma-radiation it was demonstrated that radiolytically generated superoxide released iron from ferritin with an efficiency of 67%. Lipid peroxidation strictly required both superoxide and …