Biochemistry, Biophysics, and Structural Biology Commons^™

Mechanistic Insights Into Glucan Phosphatase Activity Against Polyglucan Substrates, David A. Meekins, Madushi Raththagala, Kyle D. Auger, Benjamin D. Turner, Diana Santelia, Oliver Kötting, Matthew S. Gentry, Craig W. Vander Kooi

Molecular and Cellular Biochemistry Faculty Publications

Glucan phosphatases are central to the regulation of starch and glycogen metabolism. Plants contain two known glucan phosphatases, Starch EXcess4 (SEX4) and Like Sex Four2 (LSF2), which dephosphorylate starch. Starch is water-insoluble and reversible phosphorylation solubilizes its outer surface allowing processive degradation. Vertebrates contain a single known glucan phosphatase, laforin, that dephosphorylates glycogen. In the absence of laforin, water-soluble glycogen becomes insoluble, leading to the neurodegenerative disorder Lafora Disease. Because of their essential role in starch and glycogen metabolism glucan phosphatases are of significant interest, yet a comparative analysis of their activities against diverse glucan substrates has not been established. …

Photoacoustic Calorimetry Studies Of The Earliest Events In Horse Heart Cytochrome-C Folding, Tarah A. Word

USF Tampa Graduate Theses and Dissertations

The protein folding problem involves understanding how the tertiary structure of a protein is related to its primary structure. Hence, understanding the thermodynamics associated with the rate-limiting steps for the formation of the earliest events in folding is most crucial to understanding how proteins adopt native secondary and tertiary structures. In order to elucidate the mechanism and pattern of protein folding, an extensively studied protein, Cytochrome-c (Cc), was chosen as a folding system to obtain detailed time-resolved thermodynamic profiles for the earliest events in the protein folding process. Cytochrome-c is an ideal system for understanding the folding process for several …

A Forward Genetic Screen Identifies Factors Associated With Fever Pathogenesis In Plasmodium Falciparum, Phaedra J. Thomas

USF Tampa Graduate Theses and Dissertations

Infectious diseases that spread from person-to-person and continent-to-continent are a cause for concern for any health entity. One such disease is malaria, a mosquito-borne infection instigated by the protozoan parasite, Plasmodium falciparum. Hundreds of millions of people are affected annually and it is responsible for nearly 1 million deaths. It is the most fatal species causing malaria and proliferates in human red blood cells with a life cycle occurring every 48 hours. At this time, the parasite’s late stage form or schizont bursts from the erythrocyte releasing immune-inducing particles and infective forms (merozoites) into the bloodstream. The merozoites go …

Function Of Long Noncoding Rnas In Breast Cancer, Edward J. Richards

USF Tampa Graduate Theses and Dissertations

Breast cancer is a disease that will be diagnosed in about 1 in 10 women throughout their lifetime. The majority of breast cancers are originated from the epithelial cells of the mammary ducts, and this occurrence can be due to several factors including hereditary and acquired mutation. There are several major breast cancer subtypes, including estrogen receptor-α (ERα)-positive, HER2-enriched and triple-negative (TNBC). Patients diagnosed with ER+ tumors are generally treated with estrogen blockers (e.g., tamoxifen, letrozole and fulvestrant). Patients with HER2+ tumors are commonly administered with drugs that block HER2 signaling (e.g., trastuzumab) or inhibit HER2’s tyrosine kinase activity (e.g., …

Evaluation Of Reproductive Strategies In Captive California Yellowtail (Seriola Dorsalis) Using Genetic Parentage Analyses, Elizabeth K. Smith, Mark Drawbridge Ms, John Hyde Phd, Geoffrey Morse Phd

Theses

A good understanding of spawning dynamics of species in aquaculture is vital in order to maximize egg production and quality as well as efficient allocation of food and space resources. The breeding program of California yellowtail (CYT; Seriola dorsalis previously Seriola lalandi) at Hubbs-SeaWorld Research Institute (HSWRI) is set up such that up to 30 wild caught brood fish can broadcast spawn in a group setting, just as CYT reproduce in the wild. The population of brood fish were originally caught offshore from Southern California, and are maintained under ambient sea water and natural lighting conditions. The spawning season …

Characterizing The Rogfp2-Orp1 Fluorescent Biosensor For Detecting Oxidative Stress In Mammalian Cells, Sara A. Doan, Stevie Norcross, Mathew Tantama

The Summer Undergraduate Research Fellowship (SURF) Symposium

Parkinson’s disease is a neurodegenerative disease involving the death of neurons in the substantia nigra and loss of the neurotransmitter, dopamine. The disease leads to progressive loss of motor control. Exact causes and mechanisms by which Parkinson’s disease proceeds are unknown, however, previous experiments determine oxidative stress in mitochondria as a factor that results in cell death. Strategies have been implemented to generate fluorescent biosensors to monitor reactive oxygen species (ROS) concentrations while simultaneously measuring the spatiotemporal distribution and correlation between the ROS, cellular function and organelle. Orp1, an enzyme found in yeast, is a sensitive oxidizing species and when …

Precise Repair Of Mping Excision Sites Is Facilitated By Target Site Duplication Derived Microhomology, David M. Gilbert, M. Catherine Bridges, Ashley E. Strother, Courtney E. Burckhalter, James M. Burnette Iii, C. Nathan Hancock

Faculty Publications

A key difference between the Tourist and Stowaway families of miniature inverted repeat transposable elements (MITEs) is the manner in which their excision alters the genome. Upon excision, Stowaway-like MITEs and the associated Mariner elements usually leave behind a small duplication and short sequences from the end of the element. These small insertions or deletions known as “footprints” can potentially disrupt coding or regulatory sequences. In contrast, Tourist-like MITEs and the associated PIF/Pong/Harbinger elements generally excise precisely, returning the genome to its original state. The purpose of this study was to determine the mechanisms underlying these …

Autophagy Is Induced Upon Platelet Activation And Is Essential For Hemostasis And Thrombosis, Madhu M. Ouseph, Yunjie Huang, Meenakshi Banerjee, Smita Joshi, Laura Macdonald, Yu Zhong, Huijuan Liu, Xianting Li, Binggang Xiang, Guoying Zhang, Masaaki Komatsu, Zhenyu Yue, Zhenyu Li, Brian Storrie, Sidney W. Whiteheart, Qing Jun Wang

Molecular and Cellular Biochemistry Faculty Publications

Autophagy is important for maintaining cellular homeostasis, and thus its deficiency is implicated in a broad spectrum of human diseases. Its role in platelet function has only recently been examined. Our biochemical and imaging studies demonstrate that the core autophagy machinery exists in platelets, and that autophagy is constitutively active in resting platelets. Moreover, autophagy is induced upon platelet activation, as indicated by agonist-induced loss of the autophagy marker LC3II. Additional experiments, using inhibitors of platelet activation, proteases, and lysosomal acidification, as well as platelets from knockout mouse strains, show that agonist-induced LC3II loss is a consequence of platelet signaling …

The Energy Benefits Of The Pantograph Wing Mechanism In Flapping Flight: Case Study Of A Gull, Gene D. Sattler

Faculty Publications and Presentations

Bird wings generally contain a 4-bar pantograph mechanism in the forearm that enables the wrist joint to be actuated from the elbow joint thus reducing the number of wing muscles and hence reducing the wing inertia and inertial drag. In this paper we develop a theoretical model of inertial power for flapping flight to estimate the advantage of the 4-bar pantograph mechanism by comparing the inertial power required for the case where wrist muscles are present in the forearm with the case where wrist muscles are not present in the forearm. It is difficult to predict how wrist muscles would …

Short Communication: Lack Of Association Between Mthfr Gene Polymorphisms And Response To Methotrexate Treatment In Pakistani Patients With Rheumatoid Arthritis, Mohammad Perwaiz Iqbal, Azra Arif Ali, Naseema Mehboobali, Khalida Iqbal

Department of Biological & Biomedical Sciences

Methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms have been reported to be associated with response to methotrexate (MTX) in certain populations of patients with rheumatoid arthritis (RA). This study aims at investigating any relationship of two single nucleotide polymorphisms (SNPs) in MTHFR gene, C677T and A1298C with response to therapy with MTX in Pakistani RA patients. Allelic frequencies of the two polymorphisms (C677T and A1298C) were determined in 67 RA patients (9 males and 58 females; mean age 42.87 ± 13.5 years) who had previously participated in a prospective clinical trial. Fifty-one patients had received MTX and were followed up for response …

Coastal Sediment Elevation Change Following Anthropogenic Mangrove Clearing, Heather Lyn Hayden, Elise F. Granek

Environmental Science and Management Faculty Publications and Presentations

Coastal mangrove forests along tropical shorelines serve as an important interface between land and sea. They provide a physical buffer protecting the coastline from erosion and act as sediment “traps” catching terrestrial sediment, thus preventing smothering of subtidal coral reefs. Coastal development that removes mangrove habitat may impact adjacent nearshore coral reefs through sedimentation and nutrient loading. We examined differences in sediment elevation change between patches of open-coast intact and anthropogenically cleared red mangroves (Rhizophora mangle) on the east side of Turneffe Atoll, Belize, to quantify changes following mangrove clearing. Samples were collected over a 24 month period at five …

Wintering Bald Eagle Count Trends In The Conterminous United States, 1986-2010, Wade L. Eakle, Laura Bond, Mark R. Fuller, Richard A. Fischer, Karen Steenhof

Biomedical Research Institute Publications and Presentations

We analyzed counts from the annual Midwinter Bald Eagle Survey to examine state, regional, and national trends in counts of wintering Bald Eagles (Haliaeetus leucocephalus) within the conterminous 48 United States from 1986 to 2010. Using hierarchical mixed model methods, we report trends in counts from 11 729 surveys along 844 routes in 44 states. Nationwide Bald Eagle counts increased 0.6% per yr over the 25-yr period, compared to an estimate of 1.9% per yr from 1986 to 2000. Trend estimates for Bald Eagles were significant (P ≤ 0.05) and positive in the northeastern and northwestern U.S. …

Trim21 Regulates Nmi-Ifi35 Complex-Mediated Inhibition Of Innate Antiviral Response, Anshuman Das, Phat X. Dinh, Asit K. Pattnaik

School of Veterinary and Biomedical Sciences: Faculty Publications

In this study, using an immunoprecipitation coupled with mass spectrometry approach, we have identified the E3 ubiquitin ligase Trim21 as an interacting partner of IFI35 and Nmi. We found that this interaction leads to K63-linked ubiquitination on K22 residue of Nmi, but not IFI35. Using domain deletion analysis, we found that the interaction is mediated via the coiled-coil domain of Nmi and the carboxyl-terminal SPRY domain of Trim21. Furthermore, we show that depletion of Trim21 leads to significantly reduced interaction of Nmi with IFI35, which results in the abrogation of the negative regulatory function of the Nmi-IFI35 complex on innate …

An Allosteric Interaction Links Usp7 To Deubiquitination And Chromatin Targeting Of Uhrf1, Zhi-Min Zhang, Scott B. Rothbart, David F. Allison, Qian Cai, Joseph S. Harrison, Lin Li, Yinsheng Wang, Brian D. Strahl, Gang Greg Wang, Jikui Song

College of the Pacific Faculty Articles

The protein stability and chromatin functions of UHRF1 (ubiquitin-like, containing PHD and RING finger domains, 1) are regulated in a cell-cycle-dependent manner. We report a structural characterization of the complex between UHRF1 and the deubiquitinase USP7. The first two UBL domains of USP7 bind to the polybasic region (PBR) of UHRF1, and this interaction is required for the USP7-mediated deubiquitination of UHRF1. Importantly, we find that the USP7-binding site of the UHRF1 PBR overlaps with the region engaging in an intramolecular interaction with the N-terminal tandem Tudor domain (TTD). We show that the USP7-UHRF1 interaction perturbs the TTD-PBR interaction of …

An Analytical Method For Detecting Toxic Metal Cations Using Cyclotriveratrylene Derivative Capped Gold Nanoparticles, Zachary R. Osner, Richard C. Holz, Daniel P. Becker Ph.D.

Chemistry: Faculty Publications and Other Works

Cyclotriveratrylene-oxime (CTV-oxime) derivatives that terminate with a dithiolate linker were synthesized enabling the supramolecular scaffold to adhere to gold nanoparticles (AuNPs) with the bowl-shaped cavity of the CTV scaffold exposed for utilization in host–guest chemistry. Exposure of these CTV functionalized AuNPs to varying concentrations of di- and trivalent metal cations resulted in the formation of large CTV-AuNP polymeric clusters and an accompanying a shift in the plasmon resonance. These interactions between the CTV-AuNPs and the metal cations in solution provides proof-of-concept that supramolecular functionalized AuNPs can be used as a simple and straightforward, on-site detection system for toxic metal cations …

Short Peptides In Minimalistic Biocatalyst Design, Krystyna L. Duncan, Rein V. Ulijn

Publications and Research

We review recent developments in the use of short peptides in the design of minimalistic biocatalysts focusing on ester hydrolysis. A number of designed peptide nanostructures are shown to have (modest) catalytic activity. Five features are discussed and illustrated by literature examples, including primary peptide sequence, nanosurfaces/scaffolds, binding pockets, multivalency and the presence of metal ions. Some of these are derived from natural enzymes, but others, such as multivalency of active sites on designed nanofibers, may give rise to new features not found in natural enzymes. Remarkably, it is shown that each of these design features give rise to similar …

An Exploration Of The Phylogenetic Placement Of Recently Discovered Ultrasmall Archaeal Lineages, Jeffrey M. O'Brien

Honors Scholar Theses

In recent years, several new clades within the domain Achaea have been discovered. This is due in part to microbiological sampling of novel environments, and the increasing ability to detect and sequence uncultivable organisms through metagenomic analysis. These organisms share certain features, such as small cell size and streamlined genomes. Reduction in genome size can present difficulties to phylogenetic reconstruction programs. Since there is less genetic data to work with, these organisms often have missing genes in concatenated multiple sequence alignments. Evolutionary Biologists have not reached a consensus on the placement of these lineages in the archaeal evolutionary tree. There …

Genome-Wide Profiling Of Parp1 Reveals An Interplay With Gene Regulatory Regions And Dna Methylation, Narasimharao Nalabothula, Taha Al-Jumaily, Abdallah M. Eteleeb, Robert M. Flight, Shao Xiaorong, Hunter Moseley, Eric C. Rouchka, Yvonne N. Fondufe-Mittendorf

Molecular and Cellular Biochemistry Faculty Publications

Poly (ADP-ribose) polymerase-1 (PARP1) is a nuclear enzyme involved in DNA repair, chromatin remodeling and gene expression. PARP1 interactions with chromatin architectural multi-protein complexes (i.e. nucleosomes) alter chromatin structure resulting in changes in gene expression. Chromatin structure impacts gene regulatory processes including transcription, splicing, DNA repair, replication and recombination. It is important to delineate whether PARP1 randomly associates with nucleosomes or is present at specific nucleosome regions throughout the cell genome. We performed genome-wide association studies in breast cancer cell lines to address these questions. Our studies show that PARP1 associates with epigenetic regulatory elements genome-wide, such as active histone …

O6-Methylguanosine Leads To Position-Dependent Effects On Ribosome Speed And Fidelity, Benjamin H. Hudson, Hani S. Zaher

Biology Faculty Research

Nucleic acids are under constant assault from endogenous and environmental agents that alter their physical and chemical properties. O6-methylation of guanosine (m(6)G) is particularly notable for its high mutagenicity, pairing with T, during DNA replication. Yet, while m(6)G accumulates in both DNA and RNA, little is known about its effects on RNA. Here, we investigate the effects of m(6)G on the decoding process, using a reconstituted bacterial translation system. m(6)G at the first and third position of the codon decreases the accuracy of tRNA selection. The ribosome readily incorporates near-cognate aminoacyl-tRNAs (aa-tRNAs) by forming m(6)G-uridine codon-anticodon pairs. Surprisingly, the introduction …

Functional, Sub-100 Nm Polymer Nanoparticles Via Thiol-Ene Miniemulsion Photopolymerization, Douglas Amato, Dahlia Amato, Alex S. Flynt, Derek L. Patton

Faculty Publications

In this work, sub-100 nm crosslinked polythioether nanoparticles were synthesized via thiol–ene photopolymerization in miniemulsion using high-energy homogenization. The effects of the miniemulsion formulation and homogenization parameters – including inhibitor concentration, surfactant concentration, organic weight fraction, ultrasonication time and amplitude – on nanoparticle size and size distribution were investigated. Thiol–ene nanoparticles with a mean particle diameter of 46 nm were obtained under optimized conditions for the current system at 2.5 wt% organic fraction and 20 mM surfactant concentration. In an effort to demonstrate potential utility of thiol–ene nanoparticles, we exploit the step-growth radical mechanism of thiol–ene photopolymerization under non-stoichiometric conditions …

Intracranial Glioblastomas: New Hope For An Effective Treatment, Arthur J L Cooper

NYMC Faculty Publications

Comment on Successful Treatment of Intracranial Glioblastoma Xenografts With a Monoamine Oxidase B-Activated Pro-Drug. [EBioMedicine. 2015]

Investigation Of Behavioral And Cellular Changes In The Maternal Immune Activation Model Of Autism Spectrum Disorders, Shreya Roy

Theses & Dissertations

Maternal infection during pregnancy, which leads to maternal immune activation (MIA), is an environmental risk factor for autism spectrum disorders (ASD). MIA can be induced in mice and their offspring exhibit behaviors that model the core symptoms of ASD. One of the core behavioral symptoms in ASD patients is presence of increased repetitive behavior, which is modeled by an increase in marble burying in MIA mice. It has been shown that the deficits seen in MIA mice are associated with the dysregulation of cytokine levels in the developing brain, specifically an increase in pro-inflammatory cytokines. In this thesis, I tested …

Characterization And Target Identification Of Non-Toxic Ikkβ Inhibitors For Anticancer Therapy, Elizabeth Blowers

Theses & Dissertations

IKKβ is a key kinase in the canonical NF-κB pathway. Transient activation of IKKβ is required for normal immune response while sustained activation has been implicated in cancer. To date, no IKKβ inhibitor has been approved for clinical use as a chemotherapeutic, likely due to unexpected toxicities associated with blocking the transient activation of IKKβ. We hypothesized that an IKKβ inhibitor that allows transient activation of IKKβ, but not sustained activation of IKKβ, could inhibit cancer growth without inducing toxicity.

As such, we identified a small molecule inhibitor, 13-197, that allows the transient activation of IKKβ but not the sustained …

Transcriptional And Post-Transcriptional Regulation Of Hepcidin And Iron Metabolism By Lipid Signaling In The Liver, Sizhao Lu

Theses & Dissertations

Although iron is required for essential biological processes, excess iron is detrimental due to oxidative damage induced by iron-mediated Fenton reactions, which promote tissue injury. Cellular iron uptake, transport and storage must therefore be tightly regulated. This task is accomplished mainly through hepcidin, the key iron-regulatory hormone. Hepcidin is synthesized primarily in hepatocytes as a circulatory antimicrobial peptide. It controls iron metabolism by inhibiting iron absorption from the duodenum and iron release from reticuloendothelial macrophages. Besides synthesizing hepcidin, the liver plays an important role in maintaining iron homeostasis by serving as the main storage organ for excess iron. Patients with …

Biomass Burning Emissions And Potential Air Quality Impacts Of Volatile Organic Compounds And Other Trace Gases From Temperate Fuels Common In The United States, J. B. Gilman, B. M. Lerner, W. C. Kuster, P. D. Goldan, C. Warneke, P. R. Veres, J. M. Roberts, J. A. De Gouw, I. R. Burling, Robert Yokelson

Chemistry and Biochemistry Faculty Publications

A comprehensive suite of instruments was used to quantify the emissions of over 200 organic gases, including methane and volatile organic compounds (VOCs), and 9 inorganic gases from 56 laboratory burns of 18 different biomass fuel types common in the southeastern, southwestern, or northern United States. A gas chromatograph-mass spectrometer (GC-MS) provided extensive chemical detail of discrete air samples collected during a laboratory burn and was complemented by real-time measurements of organic and inorganic species via an open-path Fourier transform infrared spectrometer (OP-FTIR) and 3 different chemical ionization-mass spectrometers. These measurements were conducted in February 2009 at the U.S. Department …

Role Of Ime4 Protein In Pho Regulon Of S.Cerevisiae., Jenisha Ghimire

LSU New Orleans Theses and Dissertations

In the yeast Saccharomyces cerevisiae, the IME4 methyltransferase, interacts genetically with methyl binding protein, Pho92, to affect the expression of PHO regulon target genes. Cells mutant in IME4 or PHO92 show increases in the RNA abundance of PHO regulon target genes. The increase in the RNA abundance of the PHO regulon target genes is not additive in the cells double mutant in IME4 and PHO92. Hence, Ime4 and Pho92 interact in a single pathway in PHO regulon. Surprisingly, cells overexpressing IME4 and MUM2 shows increase in some PHO regulon target genes, indicating that IME4 affects the PHO regulon target …

Magnetic Nanoparticles Containing Labeling Reagents For Cell Surface Mapping, Ujwal S. Patil

LSU New Orleans Theses and Dissertations

Cell surface proteins play an important role in understanding cell-cell communication, cell signaling pathways, cell division and molecular pathogenesis in various diseases. Commonly used biotinylation regents for cell surface mapping have shown some potential drawbacks such as crossing the cell membrane, difficult recovery of biotinylated proteins from streptavidin/avidin beads, interference from endogenous biotin and nonspecific nature of streptavidin. With aim to solve these problems, we introduced sulfo-N-hydroxysuccinimidyl (NHS) ester functionalized magnetic nanoparticles containing cleavable groups to label solvent exposed primary amine groups of proteins. Silica coated iron oxide magnetic nanoparticles (Fe₃O₄@SiO₂ MNPs) were …

A Screen To Identify Saga-Activated Genes That Are Required For Proper Photoreceptor Axon Targeting In Drosophila Melanogaster, Kaelan J. Brennan, Vikki M. Weake, Jingqun Q. Ma

The Summer Undergraduate Research Fellowship (SURF) Symposium

The inherited human genetic disease spinocerebellar ataxia type 7 (SCA7) is characterized by progressive neurodegeneration and visual impairment that ultimately leads to blindness. SCA7 results from a mutation in the human ATXN7 gene that causes an expansion of polyglutamine tracts in this gene’s corresponding protein. Human ATXN7 protein serves as a component of the deubiquitylase (DUB) module of the large, multi-subunit complex Spt-Ada-Gcn acetyltransferase, or SAGA. SAGA is a transcriptional coactivator and histone modifier that functions to deubiquitylate histone H2B and allow for transcription of SAGA-mediated genes to occur. In Drosophila, mutations in SAGA DUB’s Nonstop and sgf11 components …

A Novel Synthetic Yeast For Enzymatic Biodigester Pretreatment, Tianyu Tan, Mark S. Aronson, Arren Liu, Jill H. Osterhus, Melissa Robins, Suraj Mohan, Erich Leazer, Bowman Clark, Alexa Petrucciani, Katherine Lowery, James Welch, Casey Martin, Helena Lysandrou, Michael E. Scharf, Jenna Rickus

The Summer Undergraduate Research Fellowship (SURF) Symposium

Lignin, a complex organic polymer, is a major roadblock to the efficiency of biofuel conversion as it both physically blocks carbohydrate substrates and poisons biomass degrading enzymes, even if broken down to monomer units. A pretreatment process is often applied to separate the lignin from biomass prior to biofuel conversion. However, contemporary methods of pretreatment require large amounts of energy, which may be economically uncompelling or unfeasible. Taking inspiration from several genes that have been isolated from termites and fungi which translate to enzymes that degrade lignin, we want to establish a novel “enzymatic pretreatment” system where microbes secrete these …

Viewing The Extracellular Matrix: An Imaging Method For Tissue Engineering, Michael Drakopoulos, Sarah Calve

The Summer Undergraduate Research Fellowship (SURF) Symposium

The field of regenerative medicine seeks to create replacement tissues and organs, both to repair deficiencies in biological function and to treat structural damage caused by injury. Scaffoldings mimicking extracellular matrix (ECM), the structure to which cells attach to form tissues, have been developed from synthetic polymers and also been prepared by decellularizing adult tissue. However, the structure of ECM undergoes significant remodeling during natural tissue repair, suggesting that ECM-replacement constructs that mirror developing tissues may promote better regeneration than those modeled on adult tissues. This work investigated the effectiveness of a method of viewing the extracellular matrix of developing …