Biochemistry, Biophysics, and Structural Biology Commons^™

The Lipooligosaccharides Of Haemophilus Ducreyi Are Highly Sialylated, William Melaugh, A A. Campagnari, B W. Gibson

Chemistry Faculty Publications

The major lipooligosaccharides of the sexually transmitted pathogen Haemophilus ducreyi 35000 have been previously found to terminate in N-acetyllactosamine and sialyl-N-acetyllactosamine, Neu5Ac alpha 2-->3Gal beta 1-->4GlcNAc (W. Melaugh, N. J. Phillips, A. A. Campagnari, M. V. Tullius, and B. W. Gibson, Biochemistry 33: 13070-13078, 1994). In this study, mass spectrometry and composition analyses have shown that the lipooligosaccharides from three other H. ducreyi strains also contain N-acetyllactosamine and are highly sialylated (approximately 30 to 50%), although one African strain was found to contain neither of these structural features.

Modulated Structures In Electrodeposited Superconducting Ba(1-X)K(X)Bio(3), Chad Bryant Huffman

Theses, Dissertations and Capstones

Compositionally modulated crystals of the superconductor Ba_1-x K_xBiO₃ have been grown electrochemically. Modulation was produced through control of the deposition potential.

Modulated crystals were imaged using optical microscopy, backscattered SEM, and STM. The expected linear relationship between the amount of time that current was applied and the modulation thickness was observed, and the growth rates were determined.

Multilayers were differentially etched using an EDTA solution. Etched and unetched samples were imaged using backscattered SEM.

The transition temperature of a modulated sample was determined by SQUID magnetometry to equal the bulk value.

Use Of The (3)H-Tetracycline Rat Model In The Study Of Skeletal Compartmentalization And Metabolism Of Calcium In The Maturing Male And Female Rat And The Role Of The Skeleton In Calcium Homeostasis In The Adolescent Male Rat, Darrin Lee Demoss

Theses, Dissertations and Capstones

The (3)H-tetracycline bone labeling procedure was employed to monitor bone resorption from urinary loss curves in male and female rats of various ages. In addition, whole body dry skeletal mass and the loss of (3)H-tetracycline from individual bones was determined. It was found that the dry skeletal mass/body mass ratio of 24-week-old females was 30-40% greater than that for males. The urinary loss of (3)H-tetracycline was described by a double exponential equation indicating the presence of two distinct and independent exchangeable bone compartments. Both compartments decrease in size with age, but their label loss activities were different. The label loss …

Effect Of Retinoic Acid On The Expression And Function Of Ap-1 Transcription Factor In B16 Mouse Melanoma Cells: Role Of Protein Kinase, Sejal H. Desai

Theses, Dissertations and Capstones

Retinoic acid (RA) induces differentiation of B16 mouse melanoma cells. This differentiation is accompanied by an increase in protein kinase Ca (PKCα) protein level and selective enrichment in nuclear-associated PKCα. PKC is thought to regulate gene expression through the TPA response element (TRE). This element is specifically recognized by the AP-1 transcription factor composed of jun and fos family members. In this study, I have analyzed the effect of RA on the expression and function of AP-1 in B16 mouse melanoma cells. Transient transfection analysis of B16 cells using leuciferase reporter gene constructs with or without AP-1 elements indicated that …

Regulation Of Melanogenesis In B16 Mouse Melanoma Cells By Protein Kinase C (Pkc), Harish Mahalingam

Theses, Dissertations and Capstones

The pigment cell-specific expression of tyrosinase and TRP1 has been shown to be important for the production of melanin in pigmented cells. Using a pigmented cell line, B16 mouse melanoma, we obtained evidence that PKC plays a major role in regulating melanogenesis. Chronic treatment with phorbol dibutyrate (PDBu) leads to downregulation of PKC activity and protein levels. This is accompanied by a loss of pigmentation which is correlated with a 50% reduction and a complete loss of TRP1 and tyrosinase respectively. Similar results were obtained with Northern and Western blotting indicating that PKC may regulate the steady state levels of …

Elimination Of The Chlamydomonas Gene Family That Encodes The Small Subunit Of Ribulose-1,5-Bisphosphate Carboxylaseyoxygenase, Irina Khrebtukova, Robert J. Spreitzer

Department of Biochemistry: Faculty Publications

Ribulose-1,5-bisphosphate carboxylasey oxygenase (EC 4.1.1.39) is the key photosynthetic enzyme that catalyzes the first step of CO₂ fixation. The chloroplastlocalized holoenzyme of plants and green algae contains eight nuclear-encoded small subunits and eight chloroplastencoded large subunits. Although much has been learned about the enzyme active site that resides within each large subunit, it has been difficult to assess the role of eukaryotic small subunits in holoenzyme function and expression. Small subunits are coded by a family of genes, precluding genetic screening or nuclear transformation approaches for the recovery of small-subunit mutants. In this study, the two small-subunit genes of …

Preparation And Fungitoxicity Of 3-Bromo-6-Chloro- And 6-Bromo-3-Chloro-8-Quinolinols / Gershon H., Clarke D. D., Gerhson M, Department Of Chemistry, Fordham University, Bronx, Ny 10458, Usa, New York Botanical Garden, Bronx, Ny 10458, Usa, Herman Gershon, Donald Dudley Clarke Phd, Muriel Gershon

Chemistry Faculty Publications

3-Bromo-6-chloro- and 6-bromo-3-chloro-8-nitro, -8-amino-, and -8-hydroxyquinolines along with 3-bromo- and 3-chloroquinolin-6,8-diols were prepared and tested for antifungal activity against six fungi (Aspergillus niger, A. oryzae, Myrothecium verrucaria, Trichoderma viride, Mucor cirinelloides, Trichophyton mentagrophytes) in Sabouraud dextrose broth. Compounds with chlorine in the 3 position were generally more fungitoxic than the corresponding analogues with bromine. 6-Bromo-3-chloro-8-quinolinol inhibited four fungi at levels below 1 μg/ml and A. niger and M. cirinelloides at 2 μg/ml each

Space-Based Genetic Cryoconservation Of Endangered Species, Michael Noah Mautner

Chemistry Publications

Genetic materials of endangered species must be maintained, for cryoconservation, permanently near liquid nitrogen temperatures below 77 K. Due to the instability of human institutions, permanent safety is best provided at storage sites that maintain passively the needed low temperatures, and provide barriers to access. The required conditions are available in permanently shaded polar lunar craters with equilibrium temperatures of 8 to 40 K, on the moons of Saturn, and unshielded storage satellites. A genetic depository can be incorporated readily into planned lunar programmes.

Postnatal Development Of The Neural Retina In A South American Opossum: Monodelphis Domestica, Tracy L. Soltesz

Theses, Dissertations and Capstones

Postnatal retinal development was studied in a marsupial opossum, Monodelphis domestica using light microscopy and 3H-thymidine autoradiography. For the light microscopic study, opossum neonates at 1, 3, 7, 14, 21, 25 and 28 days of age were euthanized, fixed and processed into paraffin sections for hematoxylin and eosin staining. The distinct ganglion cell layer, first observed on postnatal day (P) 7, was separated from the outer neuroblasts by the inner plexiform layer. The neuroblast layer was divided into inner and outer nuclear layers on P25 by the presumptive outer plexiform layer, indicated by discrete intercellular spaces located between the nuclear …

An Improved Synthesis Of 2-(Hydroxymethyl)Indene, Hasan Palandoken, William T. Mcmillen, Michael H. Nantz

Chemistry and Biochemistry

No abstract provided.

Patterns Of Soil Nitrogen Dynamics In A Central Appalachian Hardwood Forest Ecosystem, Bradley Michael Yurish

Theses, Dissertations and Capstones

Increasing awareness of the potential effects of acidic deposition prompted a watershed manipulation project at the Fernow Experimental Forest (FEF), West Virginia, in 1987. In this project, an acidifying agent, (Nf4)2S04 , was applied to an entire watershed to better understand ecosystem responses to simulated acid deposition in excess of ambient levels. In ecosystems receiving elevated N levels, increased soil N may contribute to soil acidification, lead to nutrient imbalances in plants, increase rates of nitrification, increase leaching of No3• and pollute surface waters. This study was designed to assess changes of three watersheds that received varied N inputs. The …

Role Of Immunodominant T Cell Responses To Minor Histocompatibility Antigens In A Mouse Model Of Graft-Versus-Host Disease, Marc Adam Berger, B.S. Thomas Jefferson University

Full-Text Theses & Dissertations

Graft-versus-host-disease (GVHD) is a major complication of major histocompatibility complex (MHC) matched bone marrow transplantation. GVHD is the result of an immune-mediated attack, by T lymphocytes derived from donor bone marrow, against recipient tissues expressing minor histocompatibility antigen (miHA) differences. There is a lack of knowledge concerning the nature of in vivo immune responses to miHA during GVHD. C57BL/6By (B6/By) and BALB.B mouse strains both express the H-2B MHC haplotype but differ at more than 40 miHA loci. Both the in vitro and in vivo T cell responses to miHA expressed by BALB.B and CXB recombinant inbred (RI) strains of …

A New High Pressure Sapphire Nuclear Magnetic Resonance Cell, Shi Bai, Craig M. Taylor, Charles L. Mayne, Ronald J. Pugmire, David M. Grant

Faculty Publications

A new version of a single-crystal sapphire high pressure nuclear magnetic resonance (NMR) cell is described that is capable of controlling the sample pressure independent of the temperature. A movable piston inside the cell adjusts and controls the sample pressure from ambient conditions to 200 atm within plus or minus 0.3 atm. The linewidth at half-height for a 13C spectrum of carbon dioxide at 15degrees C and 57.8 atm is found to be 0.5 Hz. The carbon dioxide gas/liquid phase transition is clearly observed by measuring 13C chemical shifts as the sample pressure approaches equilibrium. The time required for this …

Characterization Of The Rnasep Sequence In Chlorobium Limicola, Emily J. Hoeger

Presidential Scholars Theses (1990 – 2006)

RNAse P is a ribonucleoprotein involved in cutting out pieces of RNA. Specifically, it is involved in tRNA processing as it makes a single endonucleolytic cleavage in all precursor tRNA's to produce mature 5' ends. The sequence encoding the RNA subunit (rnpB gene) of RNAseP has been previously determined in one strain of Chlorobium limicola. A second strain was obtained from Carolina Biological Supply to test for conservation of sequence characteristics. This second strain was used in a PCR with the primers described in Haas. The amplified rnpB gene sequence appeared to have fewer base· pairs than the Haas …

Analysis Of The Mechanisms Controlling Phospholipid Biosynthetic Gene Expression In The Yeast Saccharomyces Cerevisiae, Brian Patrick Ashburner

Dissertations

No abstract provided.

The Chlorophyll Biosynthetic Enzyme Mg-Protoporphyrin Ix Monomethyl Ester (Oxidative) Cyclase, David Bollivar

Scholarship

No abstract provided.

Application Of A Modified Ziehl-Neelsen's Carbol-Fuchsin Stain For Observing Nuclei In Vegetative Hyphae Of The Puffball Species Lycoperdon Pyriforme, Martin J. Huss

Journal of the Arkansas Academy of Science

Nuclei of vegetative hyphae of the puffball species Lycoperdon pyriforme are small and difficult to stain. A simple mitotic staining technique utilizing a modified version of Ziehl-Neelsen's carbol-fuchsin stain, originally developed for examining bacteria and small chromosomes of plants, has proven useful for observing fungal nuclei in this gasteromycete species. Cells of vegetative hyphae were pre-treated for 2 hours with an aqueous solution saturated with naphthalene, fixed in a 3:1 mixture of 100% ethanol and glacial acetic acid, and hydrolyzed for 10 minutes in a 1:1 mixture of 100% ethanol and 12 M hydrochloric acid. Cells were rinsed with distilled …

Destabilizing Effect Of Proline Substitutions In Two Helical Regions Of T4 Lysozyme: Leucine 66 To Proline And Leucine 91 To Proline, Terry M. Gray, Eric Arnoys, Stephen Blankespoor, Tim Born

University Faculty Publications and Creative Works

A class of temperature-sensitive (ts) mutants of T4 lysozyme with reduced activity at 30 °C and no activity at 43 °C has been selected. These mutants, designated 'tight' ts mutants, differ from most other T4 lysozyme mutants that are active at 43 °C, but only manifest their ts lesion by a reduced halo size around phage plaques after exposure of the growth plates to chloroform vapors. For example, in the series of T4 lysozyme mutants at position 157, the original randomly selected mutant, T1571, is the least stable of the series, yet, apart from the halo assay and subsequent in …

Modulation Of Queuine Uptake And Incorporation Into Trna By Protein Kinase C And Protein Phosphatase, Rana C. Morris, Bonnie J. Brooks, K. Lenore Hart, Mark S. Elliot

Chemistry & Biochemistry Faculty Publications

It has been suggested that the rate of queuine uptake into cultured human fibroblasts is controlled by phosphorylation levels within the cell. We show that the uptake of queuine is stimulated by activators of protein kinase C (PKC) and inhibitors of protein phosphatase; while inhibitors of PKC, and down-regulation of PKC by chronic exposure to phorbol esters inhibit the uptake of queuine into cultured human fibroblasts. Activators of cAMP- and cGMP-dependent kinases exert no effect on the uptake of queuine into fibroblast cell cultures. These studies suggest that PKC directly supports the activity of the queuine uptake mechanism, and that …

Membrane Topology Of The Colicin A Pore-Forming Domain Analyzed By Disulfide Bond Engineering, Denis Duche, Jacques Izard, Juan M. Gonzalez-Manas, Michael W. Parker, Marcel Crest, Daniel Baty

Department of Food Science and Technology: Faculty Publications

Four colicin A double-cysteine mutants possessing a disulfide bond in their pore-forming domain were constructed to study the translocation and the pore formation of colicin A. The disulfide bonds connected a-helices 1 and 2, 2 and 10, 3 and 9, or 3 and 10 of the poreforming domain. The disulfide bonds did not prevent the colicin A translocation through the Escherichia coli envelope. However, the mutated colicins were able to exert their in vivo channel activity only after reduction of their disulfide bonds. In vitro studies with brominated phospholipid vesicles and planar lipid bilayers revealed that the disulfide bond that …

Bovine Cell Line Resistant To In Vtro Infection By Bovine Viral Darrheavirus And All Other Known Pestiviruses, Ruben O. Donis, Eduardo F. Flores

School of Veterinary and Biomedical Sciences: Faculty Publications

Bovine cell line resistant to infection by the pestiviruses Bovine Viral Diarrhea Virus (BVDV), Hog Cholera Virus (HCV) and Border Disease Virus (BDV) and all progeny and mutants thereof. A bovine cell line (CRIB) that is resistant to infection by cytopathic and non-cytopathic BVDV and by other Pestiviruses due to a stable, recessive genetic defect which blocks infection at the level of viral entry.

Role Of The Escherichia Coli Fadr Regulator In Stasis Survival And Growth Phase-Dependent Expression Of The Uspa, Fad, And Fab Genes, Anne Farewell, Alfredo A. Diez, Concetta C. Dirusso, Thomas Nyström

Department of Biochemistry: Faculty Publications

The increased expression of the uspA gene of Escherichia coli is an essential part of the cell’s response to growth arrest. We demonstrate that stationary-phase activation of the uspA promoter is in part dependent on growth phase-dependent inactivation or repression of the FadR regulator. Transcription of uspA is derepressed during exponential growth in fadR null mutants or by including the fatty acid oleate in the growth medium of FadR1 cells. The results of DNA footprinting analysis show that FadR binds downstream of the uspA promoter in the noncoding region. Thus, uspA is a member of the fadR regulon. All …

Rosalyn Sussman Yalow (1921-) Endocrinologist, Medical Physicist, Margaret Sylvia

Faculty Publications

A biography of Rosalyn Yalow, Nobel Prize winner in Physiology/Medicine for the development of radioimmunoassay of peptides hormones. She was the second woman to win a Nobel Prize in Medicine and first American woman to do so.

Rosalind Elsie Franklin (1920-1958) Biologist, Margaret Sylvia

Faculty Publications

A biography of the biologist Rosalind Elsie Franklin whose work on x-ray crystallography contributed to Watson and Crick's elucidation of the structure of DNA.

Mechanistic Studies On Malate Dehydrogenase From Escherichia Coli, S. Kirk Wright

Masters Theses

Kinetic studies and chemical modification studies were performed on malate dehydrogenase from Escherichia coli (eMDH). Chemical modification studies using diethylpyrocarbonate and iodoacetic acid, along with log V/K profiles indicate that one ionizing group with a pK_a between 7.9 and 8.5 acts as a general acid/base in the catalytic mechanism. Log V profiles suggest that malate binds to the correctly protonated form of the enzyme. These results imply that a histidine residue is required for catalysis.

A primary deuterium kinetic isotope effect of 1.43 (±0.14) was observed on V/K using malate-2-d, while no isotope effect was measured on V_{max …}

Developmental, Tissue, And Sub-Tissue Specific Expression Of The Mammalian Apurinic/Apyrimidinic Endonuclease, Teresa Mari Wilson

Dissertations

No abstract provided.

Regulation Of Phospholipid Biosynthesis In The Yeast Saccharomyces Cerevisiae By The Ume6 Gene, John Charles Jackson

Dissertations

No abstract provided.

Reproductive Ecology Of Pinckneya Bracteata (Bartram) Raflnesque (Rubiaceae), George H. Rountree

College of Graduate Studies: Theses & Dissertations (1964–2006)

Pinckneya bracteata is a small tree or large shrub that is indigenous to the coastal plain of extreme southern South Carolina, Georgia, and northern Florida. It in occurs in sunny, wet habitats and in small populations that are usually separated by distances of kilometers. This study examined the mating, dispersal, and germination systems of the species. Pinckneya bracteata was found to be protandrous and self incompatible. Ruby-throated Hummingbirds and bumblebees ( Bombus spp. appear to be the primary pollinators. Seed fall velocity is important to the wind dispersal of seeds and decreases as seed size increases. Fall velocity is also …

Red Blood Cell Stability In Uremic Rats, Cecilia Mermel Maccallum

Theses and Dissertations

Determining the fragility of the red blood cell (RBC) is important for the diagnosis of and evaluation for treatment of several RBC diseases. In part RBC production is controlled through the hormone erythropoietin secreted by the kidney. In a previous study from this laboratory, it was found that RBC were more stable in uremic male rats compared to controls. In this experiment, uremia was induced in four groups of female rats through a two stage nephrectomy. The nephrectomy involved the removal of two-thirds of the left kidney, followed by the removal of the entire right kidney one week later. The …

Tunable Picosecond Infrared Laser System Based On Parametric Amplification In Ktp With A Ti:Sapphire Amplifier, D. E. Gragson, D. S. Alavi, G. L. Richmond

Chemistry and Biochemistry

A picosecond laser system that will generate high-power tunable IR pulses with bandwidths suitable for spectroscopic applications is discussed. The system is based on white-light continuum generation in ethylene glycol and optical parametric amplification in potassium titanyl phosphate. The nonlinear-optical processes are driven by a regeneratively amplified Ti:sapphire laser that produces 1.7-ps pulses at a repetition rate of 1 kHz. Energies as high as 40 and 12 µJ have been achieved over the signal (1.02–1.16-µm) and idler (2.6–3.7-µm) tuning ranges, respectively. The IR beam temporal and spatial characteristics are also presented.