Biochemistry, Biophysics, and Structural Biology Commons^™

Structurally Diverse Hamigerans From The New Zealand Marine Sponge Hamigera Tarangaensis: Nmr-Directed Isolation, Structure Elucidation And Antifungal Activity, A. Jonathan Singh, Jonathan D. Dattelbaum, Jessica J. Field, Zlatka Smart, Ethan F. Woolly, Jacqueline M. Barber, Rosemary Heathcott, John H. Miller, Peter T. Northcote

Chemistry Faculty Publications

The NMR-directed investigation of the New Zealand marine sponge Hamigera tarangaensis has afforded ten new compounds of the hamigeran family, and a new 13-epi-verrucosane congener. Notably, hamigeran F (6) possesses an unusual carbon–carbon bond between C-12 and C-13, creating an unprecedented skeleton within this class. In particular, the structural features of 6, hamigeran H (10) and hamigeran J (12) imply a diterpenoid origin, which has allowed the putative biogenesis of three hamigeran carbon skeletons to be proposed based on geranyl geranyl pyrophosphate. All new hamigerans exhibited micromolar activity towards the HL-60 …

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 …

Solid-Phase Organic Matter Reduction Regulates Anaerobic Decomposition In Bog Soil, Jason K. Keller, Kimberly K. Takagi

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Peatlands store globally significant amounts of carbon and are important sources of the greenhouse gas methane (CH4) to the atmosphere. However, for reasons which are not well understood, many peatland soils produce smaller amounts of CH4 than theoretically predicted, and carbon dioxide (CO2) produced during anaerobic decomposition in peatland soils cannot be accounted for by commonly measured microbial processes. Here we show that the reduction of solid-phase organic matter (i.e., humic substances) suppresses CH4 production in a bog soil and can be responsible for 33–61% of the total carbon mineralization in this soil. These results demonstrate that the reduction of …

Decoration Of Graphene With Metal Nanoparticles And Its Application For Bioanalysis, Keun Soo Kwon

Theses, Dissertations and Culminating Projects

Graphene is a two-dimensional monolayer of tightly packed sp² hybridized Carbon atoms. Formed from graphite, the theoretical surface area of the monolayer is about 2630 m²/g, and the initial formation of graphene oxide from graphite oxide introduces a variety o f functional groups, such as -COOH, -C=0, and -OH, on its surface. The high surface area and the rich presence of functional groups, along with the potential formation o f sp² bonding networks within graphene oxide, all serve as critical factors allowing for additional chemical modifications. There are extensive research attempts being performed to explore and …

Novel Role Of Erbb-2 In Inhibition Of Jagged-1-Mediated Trans-Activation Of Notch In Breast Cancer, Kinnari Pandya

Dissertations

The ErbB-2 gene is amplified and the resulting protein product overexpressed in 15-30% of breast tumors, and associated with aggressive behavior and poor overall survival. Currently, there are two FDA approved therapies targeting ErbB-2 for the treatment of ErbB-2 positive breast cancer: trastuzumab, a humanized monoclonal antibody is directed against the extracellular domain of ErbB-2 and lapatinib, a dual EGFR/ErbB-2 tyrosine kinase inhibitor. Unfortunately, anti-ErbB-2 therapy resistance remains a major problem in metastatic breast cancer. Our data suggested that gene amplification or overexpression of ErbB-2 inhibits Notch-1 transcriptional activity and trastuzumab or lapatinib increased

Notch-1 transcriptional activity. Furthermore, Notch-1 is …

Osteogenic And Antimicrobial Nanoparticulate Calcium Phosphate And Poly-(D, L-Lactide-Co-Glycolide) Powders For The Treatment Of Osteomyelitis, Vuk Uskoković, Charles Hoover, Marija Vukomanović, Dragan P. Uskoković, Tejal A. Dasai, Charles Hoover, Marija Vukomanović, Dragan P. Uskoković, Tejal A. Dasai

Pharmacy Faculty Articles and Research

Development of a material for simultaneous sustained and localized delivery of antibiotics and induction of spontaneous regeneration of hard tissues affected by osteomyelitis stands for an important clinical need. In this work, a comparative analysis of the bacterial and osteoblastic cell response to two different nanoparticulate carriers of clindamycin, an antibiotic commonly prescribed in the treatment of bone infection, one composed of calcium phosphate and the other comprising poly-(D,L-lactide-co-glycolide)-coated calcium phosphate, was carried out. Three different non-cytotoxic phases of calcium phosphate, exhibiting dissolution and drug release profiles in the range of one week to two months to one year, respectively, …

Phase Composition Control Of Calcium Phosphate Nanoparticles For Tunable Drug Delivery Kinetics And Treatment Of Osteomyelitis. Part 2: Antibacterial And Osteoblastic Response, Vuk Uskoković, Tejal A. Dasai

Pharmacy Faculty Articles and Research

Osteomyelitis has been traditionally treated by the combination of long-term antibiotic therapies and surgical removal of diseased tissue. The multifunctional material was developed in this study with the aim to improve this therapeutic approach by: (a) enabling locally delivered and sustained release of antibiotics at a tunable rate, so as to eliminate the need for repetitive administration of systemically distributed antibiotics; and (b) controllably dissolving itself, so as to promote natural remineralization of the portion of bone lost to disease. We report hereby on the effect of the previously synthesized calcium phosphates (CAPs) with tunable solubilities and drug release time …

The Metabolic Transitions Regulated By The Estrogen-Related Receptor (Err) In Drosophila Melanogaster, Yan Li

Theses and Dissertations

In multicellular organism, bioenergetic metabolism is strictly regulated toward efficient generation of ATP. However, in certain situations, such as in limiting oxygen or in the rapidly proliferating system like growing juvenile or cancer cells, organisms apply the metabolic strategy that favors the production of biomass (e.g., nucleotides, amino acids, and lipids) over efficiency of ATP generation. The conserved estrogen-related receptors (ERRs) are master regulators in controlling metabolic homeostasis, and good candidates for mediating the metabolic transition induced by hypoxia and development. First, we investigate how dERR influences hypoxic adaptation in Drosophila melanogaster. We find that dERR is required for a …

An Investigation Of Alternative Oxidase Presence, Expression, And Regulation In The Moss Physcomitrella Patens, Karina I. Neimanis

Theses and Dissertations (Comprehensive)

Alternative oxidase (AOX) is an inner mitochondrial membrane protein that introduces a branch point at ubiquinone within the respiratory electron transport system (ETS). The AOX protein bypasses two sites of proton translocation within the ETS and as a result the yield of ATP per oxygen consumed is significantly reduced. Although AOX appears to be energetically wasteful, recent studies have revealed that AOX has a wide taxonomic distribution. AOX multigene families, transcripts, protein levels, and enzymatic activity have been most thoroughly characterized in many angiosperm (flowering) plants. Given the data available for angiosperm AOXs, evidence of non-angiosperm AOXs in the primary …

Expression And Characterization Of The Major Capsid Protein (Mcp) Of A Giant Marine Virus: Cafeteria Roenbergensis Virus, Sayan Chakraborty

Open Access Theses & Dissertations

The oceans play significant roles in maintaining the climate on Earth and providing nutrients to the whole biosphere. Oceanic microbes produce approximately half of the Earth's oxygen. It has been shown that the populations of microbial communities in oceans are largely regulated by viral infection and thus affect the marine ecosystem. Cafeteria roenbergensis Virus (CroV) is a giant marine virus with a linear, double stranded, and AT-rich DNA genome. The genome of CroV has a size of 744kb and encodes for 544 predicted genes. CroV derived its name from its host, a unicellular marine zooplankton Cafeteria roenbergensis (Cro) that is …

Role Of Post-Translational Modifications In The Hiv Cofactor Activity Of Ledgf/P75, Denisse Adriana Gutierrez

Open Access Theses & Dissertations

see document.

Sumoylation Exerts Minimal Effects On The Splicing Regulatory Activity Of The Influenza A Virus Non-Structural Protein Ns1, Griselda Melendez

Open Access Theses & Dissertations

One of the greatest challenges facing the development of a universal treatment for influenza infection is the virus's ability to mutate rapidly and produce new antigenic properties. Targeting the viral components of one strain does not ensure that the treatment will be effective with a newly developed strain. One alternative would be to develop therapies that target cellular factors the virus depends on for survivability. One of these factors is the cellular SUMOylation system. We have previously demonstrated that the Small Ubiquitin-like MOdifier (SUMO) interacts with the influenza virus by SUMOylating several viral proteins and by affecting the interferon blocking …

A Novel Fkbp52/Β-Catenin Complex Specifically Regulates Androgen Receptor Activity, Cheryl Lynne Storer

Open Access Theses & Dissertations

The androgen receptor complex plays an essential role in prostate cancer progression due to exploitation of the androgen receptor (AR) as a transcription factor. The final stage of the receptor complex consists of a dimerized receptor, a dimeric heat shock protein (Hsp90), the cochaperone p23, and an immunophilin. Hormone-dependent prostate cancer progresses due to key interactions between the androgen receptor complex and its ligand α dihydrotestosterone (DHT). While current treatments focus on blocking the androgen receptor-ligand interactions, these therapies are no longer effective in advanced stage, hormone-refractory prostate cancer (HRPC).

Therefore, we have been interested in targeting other members of …

Intercalibraton In Chemical Oceanography-- Getting The Right Number, Gregory A. Cutter

OES Faculty Publications

Intercalibration has a strict metrological definition, but in brief, it's an open sharing of methods and results between laboratories to achieve the most accurate data with the fewest random and systematic errors. In the field of chemical oceanography where concentrations of many constituents can be in the nano- to picomolar range, the salt water matrix can be difficult to analyze, and knowing the exact concentrations, or even chemical forms, of biologically required elements is essential, intercalibration is a very relevant and needed tool. Implementing it is not simple because errors can occur at any step in the process of taking …

Using Ammonium Pore Water Profiles To Assess Stoichiometry Of Deep Remineralization Processes In Methanogenic Continental Margin Sediments, David J. Burdige, Tomoko Komada

OES Faculty Publications

In many continental margin Sediments, a deep reaction zone exists which is separated from remineralization processes near the sediment surface. Here, methane diffuses upward to a depth where it is oxidized by downwardly diffusing sulfate. However, the methane sources that drive this anaerobic oxidation of methane (AOM) in the sulfate-methane transition zone (SMT) may vary among sites. In particular, these sources can be thought of as either (i) "internal" sources from in situ methanogenesis (regardless of where it occurs in the sediment column) that are ultimately coupled to organic matter deposition and burial, or (ii) "external" sources such as hydrocarbon …

Distributions Of Particulate Heme B In The Atlantic And Southern Oceans- Implications For Electron Transport In Phytoplankton, Martha Gledhill, Eric P. Achterberg, David J. Honey, Maria C. Nielsdottir, Micha J.A. Rijkenberg

OES Faculty Publications

Concentrations of heme b, the iron-containing component of b-type hemoproteins, ranged from b concentrations were enhanced in the photic zone and decreased with depth. Heme b concentrations correlated positively with chlorophyll a (chl a) in the TNA (r=0.41, pb did not correlate with chl a in the IB or SS. In the IB and SS, stations with high-chlorophyll and low-nutrient (Fe and/or Si) concentrations exhibited low heme bconcentrations relative to particulate organic carbon (< 0.1 μmolmol^-1, and high chl a:heme b ratios (> 500). High chl a:heme b ratios resulted from relative decreases in …

Boronic Acids As Penicillinase Inhibitors, Juan F. Barquero

Dissertations, Theses, and Capstone Projects

β-lactamases are enzymes produced by bacteria resistant to antibiotics. A common feature on beta lactam antibiotics is the beta-lactam ring. β-lactamases hydrolyze the β-lactam ring leaving the antibiotic inoperative. The advent of bacteria that are resistant to β-lactams has impelled researchers to find inhibitors for β-lactamases that mimic the lactam ring but do not get hydrolyzed. One group of these new antibiotics is the aryl boronic acids. The main reason the boronic acids have been chosen as potential drugs is their lack of toxicity and their easy excretion in the urine. One of the most important structural features of these …

Revisiting The Fundamentals In The Design And Control Of Nanoparticulate Colloids In The Frame Of Soft Chemistry, Vuk Uskoković

Pharmacy Faculty Articles and Research

This review presents thoughts on some of the fundamental features of conceptual models applied in the design of fine particles in the frames of colloid and soft chemistry. A special emphasis is placed on the limitations of these models, an acknowledgment of which is vital in improving their intricacy and effectiveness in predicting the outcomes of the corresponding experimental settings. Thermodynamics of self-assembly phenomena illustrated on the examples of protein assembly and micellization is analyzed in relation to the previously elaborated thesis that each self-assembly in reality presents a co-assembly, since it implies a mutual reorganization of the assembling system …