Open Access. Powered by Scholars. Published by Universities.®

Biochemistry Commons™

Open Access. Powered by Scholars. Published by Universities.®

Discipline
Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 4861 - 4890 of 6988

Full-Text Articles in Biochemistry

Sbml Qualitative Models: A Model Representation Format And Infrastructure To Foster Interactions Between Qualitative Modelling Formalisms And Tools, Claudine Chaouiya, Duncan Bérenguier, Sarah M. Keating, Aurélien Naldi, Martijn P. Van Iersel, Nicolas Rodriguez, Andreas Dräger, Finja Büchel, Thomas Cokelaer, Bryan Kowal, Benjamin Wicks, Emanuel Gonçalves, Julien Dorier, Michel Page, Pedro T. Monteiro, Axel Von Kamp, Ioannis Xenarios, Hidde De Jong, Michael Hucka, Steffen Klamt, Denis Thieffry, Nicolas Le Novère, Julio Saez-Rodriguez, Tomáš Helikar Jan 2013

Sbml Qualitative Models: A Model Representation Format And Infrastructure To Foster Interactions Between Qualitative Modelling Formalisms And Tools, Claudine Chaouiya, Duncan Bérenguier, Sarah M. Keating, Aurélien Naldi, Martijn P. Van Iersel, Nicolas Rodriguez, Andreas Dräger, Finja Büchel, Thomas Cokelaer, Bryan Kowal, Benjamin Wicks, Emanuel Gonçalves, Julien Dorier, Michel Page, Pedro T. Monteiro, Axel Von Kamp, Ioannis Xenarios, Hidde De Jong, Michael Hucka, Steffen Klamt, Denis Thieffry, Nicolas Le Novère, Julio Saez-Rodriguez, Tomáš Helikar

Department of Biochemistry: Faculty Publications

Background: Qualitative frameworks, especially those based on the logical discrete formalism, are increasingly used to model regulatory and signalling networks. A major advantage of these frameworks is that they do not require precise quantitative data, and that they are well-suited for studies of large networks. While numerous groups have developed specific computational tools that provide original methods to analyse qualitative models, a standard format to exchange qualitative models has been missing.

Results: We present the Systems Biology Markup Language (SBML) Qualitative Models Package (“qual”), an extension of the SBML Level 3 standard designed for computer representation of qualitative …


Selenodb 2.0: Annotation Of Selenoprotein Genes In Animals And Their Genetic Diversity In Humans, Frederic Romagne, Didac Santesmasses, Louise White, Gaurab K. Sarangi, Marco Mariotti, Ron Hübler, Antje Weihmann, Genis Parra, Vadim N. Gladyshev, Roderic Guigo, Sergi Castellano Jan 2013

Selenodb 2.0: Annotation Of Selenoprotein Genes In Animals And Their Genetic Diversity In Humans, Frederic Romagne, Didac Santesmasses, Louise White, Gaurab K. Sarangi, Marco Mariotti, Ron Hübler, Antje Weihmann, Genis Parra, Vadim N. Gladyshev, Roderic Guigo, Sergi Castellano

Department of Biochemistry: Faculty Publications

SelenoDB (http://www.selenodb.org) aims to provide high-quality annotations of selenoprotein genes, proteins and SECIS elements. Selenoproteins are proteins that contain the amino acid selenocysteine (Sec) and the first release of the database included annotations for eight species. Since the release of SelenoDB 1.0 many new animal genomes have been sequenced. The annotations of selenoproteins in new genomes usually contain many errors in major databases. For this reason, we have now fully annotated selenoprotein genes in 58 animal genomes. We provide manually curated annotations for human selenoproteins, whereas we use an automatic annotation pipeline to annotate selenoprotein genes in other animal genomes. …


The Basis For Limited Specificity And Mhc Restriction In A T Cell Receptor Interface, Kurt H. Piepenbrink, Sydney J. Blevins, Daniel R. Scott, Brian M. Baker Jan 2013

The Basis For Limited Specificity And Mhc Restriction In A T Cell Receptor Interface, Kurt H. Piepenbrink, Sydney J. Blevins, Daniel R. Scott, Brian M. Baker

Department of Biochemistry: Faculty Publications

αβ Tcell receptors (TCRs) recognize peptides presented by major histocompatibility complex (MHC) proteins using multiple complementarity-determining region (CDR) loops. TCRs display an array of poorly understood recognition properties, including specificity, crossreactivity and MHC restriction. Here we report a comprehensive thermodynamic deconstruction of the interaction between the A6 TCR and the Tax peptide presented by the class I MHC HLA-A*0201, uncovering the physical basis for the receptor’s recognition properties. Broadly, our findings are in conflict with widely held generalities regarding TCR recognition, such as the relative contributions of central and peripheral peptide residues and the roles of the hypervariable and germline …


Elucidating Causes Of Diporeia Decline In The Great Lakes Via Metabolomics: Physiological Responses After Exposure To Different Stressors, Suman Maity, Amber Jannasch, Jiri Adamec, James M. Watkins, Thomas Nalepa, Tomas O. Höök, Maria S. Sepúlveda Jan 2013

Elucidating Causes Of Diporeia Decline In The Great Lakes Via Metabolomics: Physiological Responses After Exposure To Different Stressors, Suman Maity, Amber Jannasch, Jiri Adamec, James M. Watkins, Thomas Nalepa, Tomas O. Höök, Maria S. Sepúlveda

Department of Biochemistry: Faculty Publications

The benthic macroinvertebrate Diporeia spp. have been extirpated from many areas of the Laurentian Great Lakes, but the mechanisms underlying such declines are not fully understood. Diporeia declines coinciding with the invasion of exotic dreissenid mussels (zebra and quagga) have led to the hypothesis that Diporeia declines are a result of decreased food availability from increasing competition with dreissenids for diatoms. There is additional evidence that Diporeia are negatively affected when in close proximity to dreissenids, probably because of exposure to toxins present in the mussels’ pseudofeces. Diporeia are also known to be sensitive to anthropogenic contaminants (such as polychlorinated …


Rna Interference Of Ctla4 In Human Leukaemia T Cells, Ralitsa Vassileva Jan 2013

Rna Interference Of Ctla4 In Human Leukaemia T Cells, Ralitsa Vassileva

Doctoral

The activation of naive T cells is essential for the initiation of the adaptive immunity. One promising approach to overcome immunological tolerance involves augmenting endogenous T cell-mediated immunity by interrupting the T cell down-regulatory pathways. In this project a gene therapy delivery system to overexpress small interfering RNA was used to silence the inhibitory signals induced by CTLA4. A small hairpin RNA duplex designed to silence expression of CTLA4 was successfully cloned into a plasmid. A stably transfected T cell line that is expressing constitutively the CTLA4 siRNA has been developed as a model to understand the role of CTLA4 …


Synthesis Of 4-Azidocoumarins And Their Use In Copper-Catalyzed Azide-Alkyne Cycloaddition Reactions, Anthony J. Netsuri Jan 2013

Synthesis Of 4-Azidocoumarins And Their Use In Copper-Catalyzed Azide-Alkyne Cycloaddition Reactions, Anthony J. Netsuri

Dissertations and Theses

Triazole-containing compounds have shown great biological activity ranging from antiviral, antibacterial, to anticancer, to name a few. Coumarin derivatives have also shown interesting biological activities. The combination of these bioactive compounds appears to have great promise for new and future medicines. In this work, various 4-azido-coumarins were synthesized via the transformation of the 4-hydroxy derivatives to 4-benzotriazolyloxy coumarins by reaction with the peptide coupling agent (benzotriazol-1-yloxy)tris-(dimethylamino)phosphonium hexafluorophosphate (BOP), and 1,8-diazabicycloundec-7-ene (DBU) as the base, in tetrahydrofuran (THF) solvent. The 4-benzotriazolyloxy coumarins were converted to the 4-azidocoumarins by reaction with sodium azide (NaN3), and the overall process was simplified to a …


Optimizing Electrode Design For Microbial Fuel Cells Used For Wastewater Treatment, Lindsay Nichols, John A. Hogan Jan 2013

Optimizing Electrode Design For Microbial Fuel Cells Used For Wastewater Treatment, Lindsay Nichols, John A. Hogan

STAR Program Research Presentations

Microbial fuel cells (MFC) utilize bacteria to generate an electrical current that can be used in the decomposition of sludge and human urine. In a MFC there is an anode (for oxidation of organic compounds), cathode (reduction of oxygen or carbon dioxide), and a proton exchange membrane (PEM, allows protons to migrate); reduction-oxidation reactions between the anode and cathode produce a measurable current. Bacteria that are found in sludge can be used to produce electrons in a voltaic cell, but optimizing conditions for harnessing the energy is crucial to making a MFC efficient. Research has shown that the ratios of …


Doxorubicin-Induced, Tnf-Α-Mediated Brain Oxidative Stress, Neurochemical Alterations, And Cognitive Decline: Insights Into Mechanisms Of Chemotherapy Induced Cognitive Impairment And Its Prevention, Jeriel T. Keeney Jan 2013

Doxorubicin-Induced, Tnf-Α-Mediated Brain Oxidative Stress, Neurochemical Alterations, And Cognitive Decline: Insights Into Mechanisms Of Chemotherapy Induced Cognitive Impairment And Its Prevention, Jeriel T. Keeney

Theses and Dissertations--Chemistry

The works presented in this dissertation provide insights into the mechanisms of chemotherapy-induced cognitive impairment (CICI or “ChemoBrain”) and take steps toward outlining a preventive strategy. CICI is now widely recognized as a complication of cancer chemotherapy experienced by a large percentage of cancer survivors. Approximately fifty percent of existing FDA-approved anti-cancer drugs generate reactive oxygen species (ROS). Doxorubicin (Dox), a prototypical ROS-generating chemotherapeutic agent, produces the reactive superoxide radical anion (O2-•) in vivo. Dox treatment results in oxidation of plasma proteins, including ApoA-I, leading to TNF-α-mediated oxidative stress in plasma and brain. TNF-α elevation in brain …


Understanding Multidrug Resistance In Gram-Negative Bacteria -- A Study Of A Drug Efflux Pump Acrb And A Periplasmic Chaperone Sura, Meng Zhong Jan 2013

Understanding Multidrug Resistance In Gram-Negative Bacteria -- A Study Of A Drug Efflux Pump Acrb And A Periplasmic Chaperone Sura, Meng Zhong

Theses and Dissertations--Chemistry

Multiple drug resistance (MDR) has been a severe issue in treatment and recovery from infection.Gram-negative bacteria intrinsically exhibit higher drug tolerance than Gram-positive microbes. In this thesis, two proteins involved in Gram-negative bacterial MDR were studied, AcrB and SurA.

Resistance-nodulation-cell division pump AcrAB-TolC is the major MDR efflux system in Gram-negative bacteria and efficiently extrudes a broad range of substances from the cells. To study subtle conformational changes of AcrB in vivo, a reporter platform was designed. Cysteine pairs were introduced into different regions in the periplasmic domain of the protein, and the extents of disulfide bond formation were …


Determination Of Structural Stabilities Of Metal-Free Porphyrin Cytochrome C, Zinc Cytochrome C, And Cobalt Cytochrome C, Usha K. Tottempudi Jan 2013

Determination Of Structural Stabilities Of Metal-Free Porphyrin Cytochrome C, Zinc Cytochrome C, And Cobalt Cytochrome C, Usha K. Tottempudi

Masters Theses

No abstract provided.


Critical Functions Specified By The Mll Cxxc Domain Determine Leukemogenic Capacity, Noah Warren Birch Jan 2013

Critical Functions Specified By The Mll Cxxc Domain Determine Leukemogenic Capacity, Noah Warren Birch

Dissertations

TheMixed Lineage Leukemia(MLL) gene can participate in chromosomal translocations which generate a fusion protein leading to acute leukemia. A better understanding of how MLL fusion proteins contribute to leukemia is necessary in order to develop more effective treatments. In my dissertation project, I investigated the functional role of amino acids within the MLL CXXC domain to determine how specific residues contribute to leukemogenic capacity.

MLL fusion proteins retain the amino-terminal portion of MLL including the CXXC DNA-binding domain while the carboxy-terminal portion is comprised of a fusion partner. The closest homolog of MLL, MLL2 (alternatively named MLL4), also contains a …


Biochemical, Structural, And Drug Design Studies Of Multi-Drug Resistant Hiv-1 Therapeutic Targets, Tamaria Grace Dewdney Jan 2013

Biochemical, Structural, And Drug Design Studies Of Multi-Drug Resistant Hiv-1 Therapeutic Targets, Tamaria Grace Dewdney

Wayne State University Dissertations

Protein point mutations acquired as a mechanism of survival against therapeutics cause structural changes that effect protein function and inhibitor binding. This work investigates the structural mechanisms that lead to multi-drug resistance to HIV-1 protease and integrase inhibitors.

Proper proteolytic processing of the HIV-1 Gag/Pol polyprotein is required for HIV infection and viral replication. This feature has made HIV-1 protease an attractive target for antiretroviral drug design for the treatment of HIV-1 infected patients, thus the development of drug resistance has arisen as a major therapeutic and drug design challenge. To understand the molecular mechanisms leading to drug resistance we …


The Cave Environment Influencing The Lipid Profile And Hepatic Lipogenesis Of The Fish Ancistrus Cryptophthalmus Reis, 1987 (Siluriformes: Loricariidae), Valquíria Aparecida Alves Bastos, Rodrigo Lopes Ferreira, Daniel Cardoso Carvalho, Marina Lages Pugedo, Luciana De Matos Alves Pinto Jan 2013

The Cave Environment Influencing The Lipid Profile And Hepatic Lipogenesis Of The Fish Ancistrus Cryptophthalmus Reis, 1987 (Siluriformes: Loricariidae), Valquíria Aparecida Alves Bastos, Rodrigo Lopes Ferreira, Daniel Cardoso Carvalho, Marina Lages Pugedo, Luciana De Matos Alves Pinto

International Journal of Speleology

The metabolism of hypogean organisms is frequently molded by the cave environment traits, especially food scarcity. The aim of the present work was to evaluate the influence of such environment on lipid composition and hepatic lipogenesis in the fish Ancistrus cryptophthalmus. For this, the species was compared to an epigean population of the same species. A greater accumulation of total lipids was observed in the cave-dwelling fish (18.36 g/100 g tissue) compared to the surface fish (14.09 g/100 g tissue). The muscle fatty acid profile also varied between the populations. Arachidonic acid was only detected in the epigean fish, while …


Biochemical Aspects Of The Thermal Sensitivity And Energy Balance Of Polar, Tropical And Subtropical Teleosts, Eloy Martinez Jan 2013

Biochemical Aspects Of The Thermal Sensitivity And Energy Balance Of Polar, Tropical And Subtropical Teleosts, Eloy Martinez

USF Tampa Graduate Theses and Dissertations

The maintenance of a functional energy balance in ectothermic fauna could be challenging in a thermally disparate environment. Biochemical adaptations at the enzyme and membrane levels allows for a set compensatory mechanism that allow the individual to maintain an energetic surplus, thus allocating energy for growth and reproduction. The present work describes how the energetic machinery in the cell, particularly the mitochondrion, could be affected by temperature changes. More specifically, this work aimed to determine how environmental temperature affects the mitochondria energetic performance of fishes from disparate thermal regimes.

Mitochondrial ATP production efficiency was evaluated in fishes from polar, tropical …


Structural Basis For Ternary Complex Formation Between Tau, Hsp90, And Fkbp51, Alexander Steven Barrett Jan 2013

Structural Basis For Ternary Complex Formation Between Tau, Hsp90, And Fkbp51, Alexander Steven Barrett

USF Tampa Graduate Theses and Dissertations

The accumulation of the microtubule associated protein tau has been implicated in several neurological disorders; however, its interaction with chaperones along its normal degradation pathway remains largely uncharacterized at single residue resolution. In this study, nuclear magnetic resonance (NMR) spectroscopy was used to probe the interaction between tau, the molecular chaperone Hsp90, and the immunophilin FKBP51. Resonance intensity changes were observed for specific residues in the heteronuclear single quantum coherence (HSQC) spectra of 15N-labeled tau in the presence of Hsp90 and/or FKBP51. Analysis of the HSQC spectra identified the two hydrophobic hexapeptide motifs located at residues V275 - K280 and …


Phosphorylation Of Histone Deacetylase 6 Within Its C-Terminal Region By Extracellular Signal Regulated Kinase 1, Kendra Allana Williams Jan 2013

Phosphorylation Of Histone Deacetylase 6 Within Its C-Terminal Region By Extracellular Signal Regulated Kinase 1, Kendra Allana Williams

USF Tampa Graduate Theses and Dissertations

http://upload.etdadmin.com/etdadmin/pdfout/222759_supp_undefined_2A63E500-E9D7-11E2-925E-BE522E1BA5B1.PDF


Immobilization And Characterization Of Physisorbed Antibody Films Using Pneumatic Spray As Deposition Technique, Jhon J. Figueroa Jan 2013

Immobilization And Characterization Of Physisorbed Antibody Films Using Pneumatic Spray As Deposition Technique, Jhon J. Figueroa

USF Tampa Graduate Theses and Dissertations

The immobilization of antibodies on silica surfaces has been a wide and common practice via cross-linking with the formation of covalent bonds between surface and antibody. The formation of antibody thin films on solid surfaces using pneumatic spray (PS) as the deposition technique and the analysis of the surface morphology of these films were investigated during this study. The pneumatic spray method was compared with the covalent bonding method Avidin-Biotin Bridge (ABB). The intensities and capture efficiency tests showed similar results for both techniques with a lower signal-to-noise ratio (SNR) for the PS deposited films. Specificity tests suggested that the …


Structural And Functional Study Of Multidrug Membrane Transporters, Feng Ding Jan 2013

Structural And Functional Study Of Multidrug Membrane Transporters, Feng Ding

Theses and Dissertations in Biomedical Sciences

Multidrug membrane transporters (efflux pumps) in both prokaryotes and eukaryotes are responsible for ineffective treatment of a wide variety of diseases, including infections and cancer, underscoring the importance of better understanding of their structures and functions for design of effective therapies. Despite extensive studies over decades, their underlying molecular mechanisms remain largely unknown. In this dissertation, we focus on the study of structures and functions of multidrug membrane transporters, including ATP-binding cassette transporter (BmrA) and Resistance-Nodulation-Cell Division transporter (MexA,B-OprM) in gram-positive and gram-negative bacteria ( Bacillus subtilis and Pseudomonas aeruginosa), respectively. We fused EGFP with N-terminus and C-terminus of …


Plant-Pathogen Interactions Associated With Wasting Disease In The Tropical Seagrass Thalassia Testudinum., Kyle Loucks Jan 2013

Plant-Pathogen Interactions Associated With Wasting Disease In The Tropical Seagrass Thalassia Testudinum., Kyle Loucks

UNF Graduate Theses and Dissertations

Lipopolysaccharide (LPS) was shown to serve as a strong elicitor of the early defense response in the subtropical seagrass Thalassia testudinum Banks ex König and was capable of inducing an oxidative burst identified at the single cell level. The formation of reactive oxygen species (ROS) included a diphenylene iodonium sensitive response, suggesting the involvement of an NADPH oxidase. A 900 bp fragment of this enzyme was sequenced and found to encode a NAD binding pocket domain with extensive homology to the Arabidopsis thaliana rbohF (respiratory burst oxidase homolog) gene. Pharmacological dissection of the early events preceding ROS emission revealed that …


Bacteriostatic Effects Of Sucralose On Environmental Bacteria, Arthur Phillip Omran Jr. Jan 2013

Bacteriostatic Effects Of Sucralose On Environmental Bacteria, Arthur Phillip Omran Jr.

UNF Graduate Theses and Dissertations

Sucralose is a zero calorie sweetener developed and manufactured by Tate and Lyle Sweetener Company in the 1980’s. They sell the sweetener compounded with maltodextrin and dextrose under the brand name Splenda®. Sucralose was developed as a low cost artificial sweetener that is non-metabolizable in humans and can withstand changes in pH and temperature. It is not degraded by the waste water treatment process. Since the molecule can withstand heat, acidification and microbial degradation it is accumulating in the environment, and has been found in waste water, estuaries, rivers and the Gulf Stream. The highest concentration of environmental sucralose detected …


Sequencing A Dna Polymerase Alpha Gene In Thermomyces Lanuginosus, Sonia Tien-Yang Han Jan 2013

Sequencing A Dna Polymerase Alpha Gene In Thermomyces Lanuginosus, Sonia Tien-Yang Han

Honors Program Theses

DNA polymerases are present in all living organisms and it is expected that there should be a reasonable degree of conservation, or similarity in how the polymerases function, between species. This makes the possibility of developing treatments using DNA polymerase more likely, as the treatment would not necessarily depend on using human DNA as the base material, which would be more expensive. However, this cannot be known unless there is a reasonable number of DNA sequences available from multiple species to analyze. This is a growing research, but the majority of sequences known are from mammals. Currently there is very …


Expressed Sequence Tag For Dna Polymerase Alpha In Embryonic Chicken Brain, Rebecca Krewer Jan 2013

Expressed Sequence Tag For Dna Polymerase Alpha In Embryonic Chicken Brain, Rebecca Krewer

Honors Program Theses

Replicative DNA polymerases are enzymes located in the nuclei of cells. They have a role in the control of DNA synthesis in all cells, and problems with their function and control affect cell growth. One of these polymerases, DNA polymerase alpha ("pol α"), is a possible point of control for cell growth because it initiates DNA synthesis. The ability to selectively turn on or shut off this polymerase in cells could provide answers to problems ranging from cancer's unregulated growth to regeneration of tissues. However, control mechanisms for DNA pol α are not fully understood at this time. The central …


New Tools For Real-Time Study Of Embryonic Development, Lauren M. Browning Jan 2013

New Tools For Real-Time Study Of Embryonic Development, Lauren M. Browning

Theses and Dissertations in Biomedical Sciences

Embryonic development represents one of the most complex and dynamic cellular processes in biology, and plays vital roles in understanding of functions of embryonic stem cells (ESCs) and design of ESC-based therapy. Conventional assays and fluorescence-based imaging methods have been widely used for the study of embryonic development. These conventional methods cannot effectively provide spatial and temporal resolutions with sufficient sensitivity and selectivity that are required to depict embryonic development in vivo in real-time at single-cell and single-molecule resolutions. In this dissertation, we have developed a wide range of innovative tools for real-time study of embryonic development. These new tools …


Intensity-Based Skeletonization Of Cryoem Gray-Scale Images Using A True Segmentation-Free Algorithm, Kamal Al Nasr, Chunmei Liu, Mugizi Rwebangira, Legand Burge, Jing He Jan 2013

Intensity-Based Skeletonization Of Cryoem Gray-Scale Images Using A True Segmentation-Free Algorithm, Kamal Al Nasr, Chunmei Liu, Mugizi Rwebangira, Legand Burge, Jing He

Computer Science Faculty Publications

Cryo-electron microscopy is an experimental technique that is able to produce 3D gray-scale images of protein molecules. In contrast to other experimental techniques, cryo-electron microscopy is capable of visualizing large molecular complexes such as viruses and ribosomes. At medium resolution, the positions of the atoms are not visible and the process cannot proceed. The medium-resolution images produced by cryo-electron microscopy are used to derive the atomic structure of the proteins in de novo modeling. The skeletons of the 3D gray-scale images are used to interpret important information that is helpful in de novo modeling. Unfortunately, not all features of the …


(R)-Β-Lysine Modified Elongation Factor P Functions In Translation Elongation, Tammy J. Bullwinkle, S. Betty Zou, Andrei Rajkovic, Steven J. Hersch, Sara Elgamal, Nathaniel Robinson, David Smil, Yuri Bolshan, William Wiley Navarre, Michael Ibba Dec 2012

(R)-Β-Lysine Modified Elongation Factor P Functions In Translation Elongation, Tammy J. Bullwinkle, S. Betty Zou, Andrei Rajkovic, Steven J. Hersch, Sara Elgamal, Nathaniel Robinson, David Smil, Yuri Bolshan, William Wiley Navarre, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Post-translational modification of bacterial elongation factor P (EF-P) with (R)-β-lysine at a conserved lysine residue activates the protein in vivo and increases puromycin reactivity of the ribosome in vitro. The additional hydroxylation of EF-P at the same lysine residue by the YfcM protein has also recently been described. The roles of modified and unmodified EF-P during different steps in translation, and how this correlates to its physiological role in the cell, have recently been linked to the synthesis of polyproline stretches in proteins. Polysome analysis indicated that EF-P functions in translation elongation, rather than initiation as proposed previously. This was …


Polyphenoloxidase And Perioxidase Activity During Open Air Ripening Storage Of Pineapple (Ananas Comosus L.), Mango (Mangifera Indica) And Papaya (Carica Papaya) Fruits Grown In Dar Es Salaam, Tanzania, Oc Othman Dec 2012

Polyphenoloxidase And Perioxidase Activity During Open Air Ripening Storage Of Pineapple (Ananas Comosus L.), Mango (Mangifera Indica) And Papaya (Carica Papaya) Fruits Grown In Dar Es Salaam, Tanzania, Oc Othman

Tanzania Journal of Science

Polyphenoloxidase (PPO) and perioxidase (POD), the enzymes responsible for causing browning and change in texture and flavor of fruits and vegetables, were extracted and measured in harvested mature pineapple (Ananas comosus L.), mango (Mangifera indica) (Viringe and Dodo varieties) and papaya (Carica papaya) fruits during off vine, open air, room temperature ripening storage. The initial (at harvest) average PPO activity values in Δ Optical Density (OD) per minute per cm3 of enzyme solution were 0.00074, 0.00083 and 0.0010 for early, mid and late season pineapple fruits respectively. The initial average PPO activity values in ΔOD/min/ cm3 of enzyme solution were …


A Comparison Of Boltzmann And Gibbs Definitions Of Microcanonical Entropy For Small Systems, Randall B. Shirts Dec 2012

A Comparison Of Boltzmann And Gibbs Definitions Of Microcanonical Entropy For Small Systems, Randall B. Shirts

Faculty Publications

Two different definitions of entropy, S= klnW, in the microcanonical ensemble have been competing for over 100 years. The Boltzmann/Planck definition is that W is the number of states accessible to the system at its energy E (also called the surface entropy). The Gibbs/Hertz definition is that W is the number of states of the system up to the energy E (also called the volume entropy). These two definitions agree for large systems but differ by terms of order N-1 for small systems, where N is the number of particles in the system. For three analytical …


Cloning, Expression, And Characterization Of Ara H 3, A Major Peanut Allergen, Cathryn E. Garvey Dec 2012

Cloning, Expression, And Characterization Of Ara H 3, A Major Peanut Allergen, Cathryn E. Garvey

LSU New Orleans Theses and Dissertations

Abstract There are eight foods that contribute to food allergies in the western world and peanut is the most common. Currently, there are no medical treatments that can cure an individual of food allergy, so avoidance of the allergic food is the only option. In the United States, there are three immunodominant allergic proteins accountable for patient sensitization to peanut, Arachis hypogea 1, 2, and 3 (Ara h 1, Ara h 2, Ara h 3). Therefore, research into why peanuts are more allergic than other foods that have homologous proteins is critical and may be obtained by studying the structural …


Crystal Structures And Kinetics Of Monofunctional Proline Dehydrogenase Provide Insight Into Substrate Recognition And Conformational Changes Associated With Flavin Reduction And Product Release, Min Luo, Benjamin W. Arentson, Dhiraj Srivastava, Donald F. Becker, John J. Tanner Dec 2012

Crystal Structures And Kinetics Of Monofunctional Proline Dehydrogenase Provide Insight Into Substrate Recognition And Conformational Changes Associated With Flavin Reduction And Product Release, Min Luo, Benjamin W. Arentson, Dhiraj Srivastava, Donald F. Becker, John J. Tanner

Department of Biochemistry: Faculty Publications

Proline dehydrogenase catalyzes the FAD-dependent oxidation of proline to Δ1- pyrroline-5- carboxylate, which is the first step of proline catabolism. Here, we report the structures of proline dehydrogenase from Deinococcus radiodurans in the oxidized state complexed with the proline analog L-tetrahydrofuroic acid and in the reduced state with the proline site vacant. The analog binds against the si face of the FAD isoalloxazine and is protected from bulk solvent by the α8 helix and the β1-α1 loop. The FAD ribityl chain adopts two conformations in the E-S complex, which is unprecedented for flavoenzymes. One of the conformations is novel for …


Microfluidic Devices With Integrated Sample Preparation For Improved Analysis Of Protein Biomarkers, Pamela Nsang Nge Dec 2012

Microfluidic Devices With Integrated Sample Preparation For Improved Analysis Of Protein Biomarkers, Pamela Nsang Nge

Theses and Dissertations

Biomarkers present a non-invasive means of detecting cancer because they can be obtained from body fluids. They can also be used for prognosis and assessing response to treatment. To limit interferences it is essential to pretreat biological samples before analysis. Sample preparation methods include extraction of analyte from an unsuitable matrix, purification, concentration or dilution and labeling. The many advantages offered by microfluidics include portability, speed, automation and integration. Because of the difficulties encountered in integrating this step in microfluidic devices most sample preparation methods are often carried out off-chip. In the fabrication of micro-total analysis systems it is important …