Biochemistry, Biophysics, and Structural Biology Commons^™

Expression Of Cholera Toxin B Subunit-Rotavirus Nsp4 Enterotoxin Fusion Protein In Transgenic Chloroplasts, Anila Kalluri

Electronic Theses and Dissertations

Rotavirus, the major cause of life-threatening infantile gastroenteritis, is a member of the Reoviridae family and is considered to be the single most important cause of virus-based severe diarrheal illness in infants and young children particularly 6 months to 2 years of age in industrialized and developing countries. Infection in infants and young children is often accompanied by severe life threatening diarrhea, most commonly following primary infection. Diarrhea is the major cause of death among children around the world. Responsible for 4 to 6 million deaths per year according to the World Health Organization (WHO), diarrhea is especially dangerous for …

Receptor Mediated Oral Delivery Of Bioencapsulated Green Fluorescent Protein Expressed In Transgenic Chloroplasts, Arati Limaye

Electronic Theses and Dissertations

The skyrocketing costs of prescription medicine in developed countries and their lack of availability in developing countries are the most challenging problems of human health. Primary reasons for such high cost are fermentation-based production, expensive purification methods, the need for low temperature storage and transportation and the delivery through sterile injections. Most of these expenses could be minimized or eliminated when therapeutic proteins are expressed and orally delivered via plant cells. Chloroplasts have the machinery to fold complex and biologically active eukaryotic proteins in the soluble chloroplast stromal compartment. Protein expression through chloroplast transformation system offers a number of advantages …

Correction Of The Literature Citing Monoiodo-8-Quinolinols: A Critical Review / Herman Gershon And Donald D. Clarke Harding Laboratory, The New York Botanical Garde, And Fordham University, Bronx, New York 10458, Usa, Herman Gershon, Donald Dudley Clarke Phd, Donald Dudley Clarke Phd

Chemistry Faculty Publications

Until 1995, all papers that claimed preparation or further study with monoiodo-8-quinolinol were really working with the 7-iodo isomer. Of the 83 relevant citations 67 dealt with incorrect structural assignments, 13 were critiqued due to errors made in synthesis and interpretation, and 9 had the correct structural assignments. This literature review made the following conclusions apparent. 1. Prototropic forms of 8- quinolinol influence orientation of electrophiles. 2. Under strong acidic conditions, the 5 position is favored. 3. Under mild acidic conditions, mixtures of 5 and 7 substituted compounds are formed. 4. Under basic conditions, the incoming electrophile favors the 7 …

Protein Sequence Entropy Is Closely Related To Packing Density And Hydrophobicity, H Liao, W Yeh, D Chiang, R L. Jernigan, Brooke Lustig

Faculty Publications, Chemistry

We investigated the correlation between the Shannon information entropy, ‘sequence entropy’, with respect to the local flexibility of native globular proteins as described by inverse packing density. These are determined at each residue position for a total set of 130 query proteins, where sequence entropies are calculated from each set of aligned residues. For the accompanying aggregate set of 130 alignments, a strong linear correlation is observed between the calculated sequence entropy and the corresponding inverse packing density determined at an associated residue position. This region of linearity spans the range of Cα packing densities from 12 to 25 amino …

Removal Of P-Cresol Sulfate By Hemodialysis, Andres W. Martinez, Natalie S. Recht, Thomas H. Hostetter, Timothy W. Meyer

Chemistry and Biochemistry

Protein-bound solutes are poorly cleared by dialysis. Among the most extensively studied of these solutes is p-cresol, which has been shown to be toxic in vitro. This study examined the form in which p-cresol circulates and quantified its removal by hemodialysis. HPLC analysis of plasma from hemodialysis patients contained a peak whose mobility corresponded to synthetic p-cresol sulfate (PCS) but no detectable unconjugated p-cresol. Treatment with sulfatase resulted in recovery of this peak as p-cresol, confirming its identity. Subsequent studies compared the removal of PCS and another protein-bound solute, indican, to the removal of urea during clinical hemodialysis treatments. …

Selenotrisulfide Derivative Of Alpha-Lipoic Acid: Evaluation In A Cell Culture Model For Potential Use As A Topical Antioxidant, Melenie Lee Alonis

Electronic Theses and Dissertations

Selenium is a required micronutrient in mammalian cells. It is incorporated in the form of selenocysteine into selenoenzymes such as glutathione peroxidase and thioredoxin reductase, and is absolutely required for activity. Thioredoxin reductase is necessary for reduction of oxidized thioredoxin and therefore plays a major role in maintaining the redox status of the cell. Glutathione peroxidase is responsible for reducing peroxides into their corresponding alcohols and water. Together, these selenoenzymes constitute a significant part of the cell's arsenal to defend itself against oxidative stress. Exogenous sources of oxidative stress, such as UV radiation, are capable of generating reactive oxygen species …

Reduced Macrophage Apoptosis Is Associated With Accelerated Atherosclerosis In Low-Denstiy Lipoprotein Receptor-Null Mice, Michael Sinensky, J. Liu, D. P. Thweke, Y. R. Su, M. F. Linton, S. Fazio

Faculty Publications, Biological Sciences

Objective— The majority of apoptotic cells in atherosclerotic lesions are macrophages. However, the pathogenic role of macrophage apoptosis in the development of atherosclerosis remains unclear. Elevated expression of Bax, one of the pivotal proapoptotic proteins of the Bcl-2 family, has been found in human atherosclerotic plaques. Activation of Bax also occurs in free cholesterol-loaded and oxysterol-treated mouse macrophages. In this study, we examined the effect of Bax deficiency in bone marrow-derived leukocytes on the development of atherosclerosis in low-density lipoprotein receptor-null (LDLR−/−) mice. Methods and Results— Fourteen 8-week-old male LDLR−/− mice were lethally irradiated and reconstituted with either wild-type (WT) …

China Lake Buffer Strip Pictures, Colby Environmental Assessment Team, Colby College, Problems In Environmental Science Course (Biology 493), Colby College

Colby College Watershed Study: China Lake (2005, 1989)

No abstract provided.

Ethan's Land Use Photos, Colby Environmental Assessment Team, Colby College, Problems In Environmental Science Course (Biology 493), Colby College

Colby College Watershed Study: China Lake (2005, 1989)

No abstract provided.

Analysis Of Genotypic And Phenotypic Differences In Desmognathus Quadramaculatus Across The Southern Appalachians, Deborah Susan Merritt

Theses, Dissertations and Capstones

Populations of Desmognathus quadramaculatus were compared for genotypic and phenotypic differences across 5 states in the Southern Appalachians. Series consisting of 10 salamanders each were collected from West Virginia, Virginia, Tennessee, North Carolina and Georgia. Salamanders were assessed for genotypic differences by using allozyme (proteins with polymorphic loci) electrophoresis staining for 13 loci of the muscle, liver and stomach tissue. Nei’s genetic distance was used to score genetic variation between populations. Phenotypic differences were assessed by comparing 10 external morphological measurements between populations. Mahalanobis’ distance was used to score morphological differences between populations. Both genetic and morphological differences were correlated …

Computational Study Of A Novel Dinuclear Metal Complex, Dragos Seghete

Inquiry: The University of Arkansas Undergraduate Research Journal

The first compound containing an M-H-M was recently reported by Vicic et al. With recent availability of large computational resources, molecular modeling has become a reliable tool for confirming experimental results. The novel dinuclear Ni complex [( dippm)2Ni2Br2]( 0 -H) was investigated in this work from a theoretical perspective. Full geometry optimization was carried on the dinuclear Ni complex at the DFT/B3LYP with the 6-31G* basis set. The result verifies the linear Ni-H-Ni bond. Two different starting structures that converged to the same geometry confirm that a global minimum was reached. The computed structure differs from the experimentally determined one …

Biphasic Functions Of The Kinase-Defective Ephb6 Receptor In Cell Adhesion And Migration, Hiroshi Matsuoka, Hiroya Obama, Meghan Kelly, Toshimitsu Matsui, Masaru Nakamoto

Biology Faculty Publications

EphB6 is a unique member in the Eph family of receptor tyrosine kinases in that its kinase domain contains several alterations in conserved amino acids and is catalytically inactive. Although EphB6 is expressed both in a variety of embryonic and adult tissues, biological functions of this receptor are largely unknown. In the present study, we examined the function of EphB6 in cell adhesion and migration. We demonstrated that EphB6 exerted biphasic effects in response to different concentrations of the ephrin-B2 ligand; EphB6 promoted cell adhesion and migration when stimulated with low concentrations of ephrin-B2, whereas it induced repulsion and inhibited …

Selective Field Effects On Intracellular Vacuoles And Vesicle Membranes With Nanosecond Electric Pulses, Ephrem Tekle, Hammou Oubrahim, Sergey M. Dzekunov, Juergen F. Kolb, Karl H. Schoenbach

Bioelectrics Publications

Electric pulses across intact vesicles and cells can lead to transient increase in permeability of their membranes. We studied the integrity of these membranes in response to external electric pulses of high amplitude and submicrosecond duration with a primary aim of achieving selective permeabilization. These effects were examined in two separate model systems comprising of 1), a mixed population of 1,2-di-oleoyl-sn-glycero-3-phosphocholine phospholipid vesicles and in 2), single COS-7 cells, in which large endosomal membrane vacuoles were induced by stimulated endocytosis. It has been shown that large and rapidly varying external electric fields, with pulses shorter than the charging time of …

Diversity And Functional Plasticity Of Eukaryotic Selenoproteins: Identification And Characterization Of The Selj Family, Sergi Castellano, Alexey V. Lobanov, Charles Chapple, Sergey V. Novoselov, Mario Albrecht, Deame Hua, Alain Lescure, Thomas Lengauer, Alain Krol, Vadim N. Gladyshev, Roderic Guigó

Department of Biochemistry: Faculty Publications

Selenoproteins are a diverse group of proteins that contain selenocysteine (Sec), the 21st amino acid. In the genetic code, UGA serves as a termination signal and a Sec codon. This dual role has precluded the automatic annotation of selenoproteins. Recent advances in the computational identification of selenoprotein genes have provided a first glimpse of the size, functions, and phylogenetic diversity of eukaryotic selenoproteomes. Here, we describe the identification of a selenoprotein family named SelJ. In contrast to known selenoproteins, SelJ appears to be restricted to actinopterygian fishes and sea urchin, with Cys homologues only found in cnidarians. SelJ shows significant …

Computer-Assisted Docking Of Flavodoxin With The Atp:Co(I)Rrinoid Adenosyltransferase (Coba) Enzyme Reveals Residues Critical For Protein-Protein Interactions But Not For Catalysis, Nicole R. Baun, Jorge C. Escalante-Semerena

Department of Biochemistry: Faculty Publications

The activity of the housekeeping ATP:co(I)rrinoid adenosyltransferase

(CobA) enzyme of Salmonella enterica sv. Typhimurium

is required to adenosylate de novo biosynthetic intermediates

of adenosylcobalamin and to salvage incomplete and complete

corrinoids from the environment of this bacterium. In vitro,

reduced flavodoxin (FldA) provides an electron to generate the

co(I)rrinoid substrate in the CobA active site. To understand how

CobAand FldA interact, a computer model of aCobA-FldA complex

was generated. This model was used to guide the introduction of

mutations into CobA using site-directed mutagenesis and the synthesis

of a peptide mimic of FldA. Residues Arg-9 and Arg-165 of

CobA …

The Effects Of Β-Mercaptoethanol On The Specific Activity Of Porphobilinogen Synthase Mutants Of The Rhodobacter Sphaeroides Protein, Trefan Archibald '05

Honors Projects

The enzyme porphobilinogen synthase (PBGS) catalyzes the conversion of two molecules of δ-aminolevulinic acid (ALA) into porphobilinogen (PBG) in the first common step of the tetrapyrrole biosynthesis pathway. A homology model of the R. sphaeroides PBGS was created by Dr. Eileen K. Jaffe at Fox Chase Cancer Center based on comparison to the crystal structure of Pseudomonas aeruginosa. The proposed structure suggests that there are four cysteines in close proximity to the active site. Three of these cysteines are not present in the highly similar R. capsulatus sequence. Under oxidizing conditions these residues can potentially participate in the formation of …

Characterisation Of The Cinnamyl Alcohol Dehydrogenase From Helicobacter Pylori, Blanaid Mee

Doctoral

Cinnamyl alcohol dehydrogenases (CAD; 1.1.1.195) catalyse the conversion of p-hydroxy-cinnamaldehydes to their corresponding alcohols leading to the biosynthesis of lignin in plants. Outside of plants their role is less well defined. The cinnamyl alcohol dehydrogenase from H. pylori (HpCAD) has been cloned and produced in E. coli and characterised for substrate specificity. The enzyme is a monomer of 42.5 kDa found predominantly in the cytosol of the bacterium. It is specific for NADP(H) as cofactor and has a broad substrate specificity for alcohol and aldehyde substrates. Its substrate specificity is similar to the well-characterised plant enzymes. The best alcohol substrate …

Determination Of The Regions Related To Nuclear Localization Of The Poly C Binding Protein, Andrea M. Berry

Seton Hall University Dissertations and Theses (ETDs)

No abstract provided.

Stm And Computational Investigations Of Nanostructured Layered Transition Metal Chalcogenides, Changki Kim

Seton Hall University Dissertations and Theses (ETDs)

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Synthesis Of Novel Porphyrazines And Binding Studies To Dna Quadruplexes, Carlos Ramirez

Seton Hall University Dissertations and Theses (ETDs)

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New Insights Into Bile Acid Amidation, Mary Hunt, Eithne O'Shea, Karianne Solaas, Bengt Kase, Stefan Alexson

Articles

No abstract provided.

Identification Of The Pla2 Responsible For Prostanoid Synthesis In Response To Inflammatory Cytokines, Chaminda Fernando

Theses and Dissertations

Preliminary studies from our laboratory showed that cPLA2α may be responsible for approximately 50-60% of the PGE2 production in response to inflammatory cytokines. Thus, we hypothesized that a closely-related PLA2 is responsible for 40-50% of the PGE2 produced in response to inflammatory cytokines. To this end, we utilized RNAi technology, extensively optimized, to down regulate the expression of closely-related isoforms of phospholipase A2 in A549 cells and used an enzyme linked immuno sorbent assay (ELISA) to quantitate the PGE2 produced. These studies found that cytosolic phospholipase A2α (cPLA2α) regulated 97.7% of the prostaglandin E2 (PGE2) produced in response to inflammatory …

Mapping Of Ssdna Nicks Within Dsdna Genomes By Two-Dimensional Gel Electrophoresis, Wayne P. Wahls, K. Mark Dewall, Mari K. Davidson

Journal of the Arkansas Academy of Science

DNA molecules within chromosomes undergo constant, dynamic changes yet maintain the integrity of the primary DNA sequence. DNA replication, adjustment of helical density, resolution of catenenes, repair of DNA damage, and homologous recombination each involve breakage and religation of the phosphate backbone of the double helix. Although the analysis of dsDNA breaks is facile, the analysis of ssDNA nicks is not. The principal impediment is that conventional, one-dimensional electrophoresis methods cannot readily detect ssDNA nicks in the context of dsDNA breaks. We therefore developed a two dimensional (native/denaturing) gel electrophoresis approach to map the positions of ssDNA nicks. Analysis of …

Quality Control During Aminoacyl-Trna Synthesis, M. Praetorius-Ibba, S. Ataide, C. Hausmann, J. Levengood, J. Ling, S. Wang, H. Roy, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The fidelity of translation is determined at two major points: the accuracy of aminoacyl-tRNA selection by the ribosomes and synthesis of cognate amino acid/tRNA pairs by aminoacyl-tRNA synthetases (aaRSs) in the course of the aminoacylation reaction. The most important point in aminoacylation is the accurate recognition of cognate substrates coupled with discrimination of non-cognates. While this is generally accomplished by a single enzyme, we have recently found that discrimination against lysine analogues requires the existence of two unrelated lysyl-tRNA synthetases. For other amino acids, initial recognition is not sufficiently accurate with errors being corrected by an intrinsic editing activity. Recent …

Effect Of Humic Substance Photodegradation On Bacterial Growth And Respiration In Lake Water, Alexandre M. Anesio, William Granéli, George R. Aiken, David J. Kieber, Kenneth Mopper

Chemistry & Biochemistry Faculty Publications

This study addresses how humic substance (HS) chemical composition and photoreactivity affect bacterial growth, respiration, and growth efficiency (BGE) in lake water. Aqueous solutions of HSs from diverse aquatic environments representing different dissolved organic matter sources (autochthonous and allochthonous) were exposed to artificial solar UV radiation. These solutions were added to lake water passed through a 0.7-μm pore-size filter (containing grazer-free lake bacteria) followed by dark incubation for 5, 43, and 65 h. For the 5-h incubation, several irradiated HSs inhibited bacterial carbon production (BCP) and this inhibition was highly correlated with H₂O₂ photoproduction. The H_{2 …}

In Vivo Role Of 20-Hydroxyecdysone In The Regulation Of The Vitellogenin Mrna And Egg Development In The American Dog Tick, Dermacentor Variabilis (Say), Deborah M. Thompson, Sayed M.S. Khalil, Laura A. Jeffers, Usha Ananthapadadmanaban, Daniel E. Sonenshine, Robert D. Mitchell, Christopher J. Osgood, Charles S. Apperson, R. Michael Roe

Biological Sciences Faculty Publications

Injection of the hormone 20-hydroxyecdysone (20-E) into partially fed (virgin) female adults of the American dog tick, Dermacentor variabilis, while they are attached and feeding on the rabbit host, initiated the expression of the vitellogenin (Vg) gene, and Vg protein secretion and uptake by the ovary. The induction of egg production by 20-E in this bioassay was dose dependent in the range of 1-50 times the concentration normally found in a replete, vitellogenic female. Ticks examined 4d after the 50x treatment were still attached to the host, had numerous enlarged vitellin-filled (brown) oocytes in their ovaries, but had not …

Arsenite Regulates Cystic Fibrosis Transmem­Brane Conductance Regulator And P-Glycoprotein: Evidence Of Pathway Independence, Rangan Maitra, Joshua Hamilton

Dartmouth Scholarship

In the past, people have argued for and against the theory of reciprocal regulation of the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) and P-glycoprotein (Pgp). Data have indicated that this may occur in vitro during drug-induced selection of cells, and in vivo during development. Much of this debate has been caused by a severe lack of mechanistic details involved in such regulation. Our past data indicate that certain Pgp modulators can affect CFTR expression and function. The goal of this study was to investigate the effects of trivalent arsenic (arsenite), a known transcriptional activator of Pgp, on CFTR expression. In …

A Novel Binding Interaction For The Paxillin Ld3 Motif: Paxillin Ld3 Mediates Merlin-Paxillin Binding At Paxillin Binding Domain 1, Sandra E. Beattie Geden

Electronic Theses and Dissertations

Neurofibromatosis type 2, an autosomal dominant genetic disorder, causes predisposed individuals to develop various benign central and peripheral nervous system tumors. The characteristic tumors of this disease are schwannomas, which are tumors of the Schwann cells, typically on the vestibular nerve. These and the other associated tumors slowly compress nervous system structures causing deafness and loss of balance, resulting in an average life-span of less than 40 years. The product of the Nf2 gene is the protein named merlin or schwannomin. In individuals diagnosed with NF2, merlin is either absent or mutated to the point of inactivation. As such, merlin …

Vimentin Overexpression Contributes To The Biological Properties Of Metastatic Head And Neck Cancer Cells, Rachel J. Paccione

Theses and Dissertations

Epithelial to mesenchymal transition occurs in the later stages of epithelial tumor progression, with cells expressing mesenchymal markers. Of these, the intermediate filament protein vimentin is frequently upregulated in metastatic carcinomas. Previously, microarray studies showed that the gene encoding vimentin is highly upregulated in metastatic HN12 cells compared to a related primary tumor cell line. In this study, we confirmed this difference using real-time quantitative PCR, western blot analysis, and immunostaining. Furthermore, EGF and TGF-β, growth factors that induce migration and invasion of HN12 cells, produced synergistic increases in vimentin expression. To assess the contribution of vimentin to the biological …

Modulation Of Gene Expression By Tumor-Derived Mutant P53. Role Of Transactivation In Gain-Of-Function., Mariano J. Scian

Theses and Dissertations

It was hypothesized that the C-terminal sequences for mutant p53 would be required for oligomerization. and oligomerization may be critical for gain-of-function. An N-terminal deletion mutant of p53 that deletes amino acids 1-293 was used as a tool to perform hetero-oligomerization studies. This mutant retains the entire oligomerization domain but dispenses off the transactivation domain and a large portion of the sequence- specific DNA-binding domain. Co-transfection experiments show that p53 del. 1-293 forms hetero-oligomeric complexes with p53-D281G. Also. co-expression of p53 del. 1- 293 with p53-D281G inhibited p53-D28lG-mediated transactivation of the EGFR and MDRl promoters suggesting that hetero-oligomerization inactivates transcriptional …