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Full-Text Articles in Biochemistry

Copper-Mediated Regulation Of A Traditional Iron Uptake System In Uropathogenic Escherichia Coli., George Lwanga Katumba Aug 2021

Copper-Mediated Regulation Of A Traditional Iron Uptake System In Uropathogenic Escherichia Coli., George Lwanga Katumba

Arts & Sciences Electronic Theses and Dissertations

Transition metals constitute an important part of the host-pathogen interface. Iron is an essential nutrient that functions as a cofactor for numerous bacterial and host proteins, as either a ligand for oxygen in carrier proteins or an enzyme catalytic site due to its natural redox properties. As part of the innate immune response, infected hosts sequester iron from pathogens to limit their growth, a phenomenon known as nutritional immunity. On the other hand, copper ions are deployed at infection sites as a potent antimicrobial agent to kill bacteria. The ability to survive within multiple, often harsh, microenvironments is fundamental to …


The Regulation Of Plasmodium Falciparum Metabolism By Haloacid Dehalogenase Proteins, Philip Frasse Aug 2021

The Regulation Of Plasmodium Falciparum Metabolism By Haloacid Dehalogenase Proteins, Philip Frasse

Arts & Sciences Electronic Theses and Dissertations

Malaria is an enormous financial and public health burden for much of the world, infecting over 200 million and killing over 400,000 people every year. While much progress has been made combating malaria in the past few decades, those advances have slowed in recent years, partially due to the emergence of resistance to all known antimalarials used to date. To achieve the goal of eliminating malaria as a major global health problem, new therapeutics need to be developed, targeting novel categories of parasite biology. One poorly understood area of parasite biology is the regulation of various metabolic pathways. We have …


Prodrug Activation In Staphylococci And The Implications For Antimicrobial Development, Justin J. Miller Jan 2021

Prodrug Activation In Staphylococci And The Implications For Antimicrobial Development, Justin J. Miller

Arts & Sciences Electronic Theses and Dissertations

Antibiotic resistance is an increasing concern for global health care, with some estimates suggesting that 10 million people will die from antibiotic resistant infections in the year 2050. Fueling this prospect, few antimicrobials are being actively developed and recently commercial entities have fled from the development of new anti-infectives. New antimicrobials and drug development strategies are urgently needed to revitalize this critical pipeline. While many putative antibiotics demonstrate promising in vitro potency, they routinely fail in vivo due to poor drug-like properties (e.g. oral bioavailability, serum-half life, toxicity) resulting in overly expensive drug development pipelines. Fortunately, drug-like properties can be …


Understanding The Molecular Mechanisms Of Photoferrotrophy And Phototrophic Extracellular Electron Uptake, Dinesh Gupta Jan 2021

Understanding The Molecular Mechanisms Of Photoferrotrophy And Phototrophic Extracellular Electron Uptake, Dinesh Gupta

Arts & Sciences Electronic Theses and Dissertations

Several anoxygenic phototrophs grow by utilizing soluble iron or insoluble mixed-valence iron minerals (such as rust) as electron donors to fix carbon dioxide using light energy, a process called photoferrotrophy. Photoferrotrophs can also use electron donors such as poised electrodes that serve as proxies for rust via phototrophic extracellular electron uptake (EEU). Despite the recognition that these two related microbial processes contribute to various biogeochemical cycles such as iron and carbon, the electron uptake mechanisms underlying photoferrotrophy and phototrophic EEU are poorly understood. To address the key knowledge gaps in our understanding of these microbial metabolisms, here we characterized Rhodopseudomonas …


Molecular Insights Into Microbial Adhesion, Roger Davies Klein May 2020

Molecular Insights Into Microbial Adhesion, Roger Davies Klein

Arts & Sciences Electronic Theses and Dissertations

Antibiotic-resistant bacterial infections are a serious and immediate threat to global public health. In the United States alone, over 2 million individuals develop antibiotic-resistant infections annually, resulting in 23,000 deaths and $20 billion in excess health care costs. Virulence factors that allow bacteria to invade and persist within the host are promising targets for novel antimicrobial agents that could be used to curb the spread of antibiotic resistance. Development of therapeutics that can selectively eliminate pathogenic bacteria while sparing the beneficial host microbiota requires a detailed molecular understanding of critical virulence factors that facilitate interactions between pathogens and their environments. …


Diverse Far-Red Light Utilization Strategies In Cyanobacteria And Algae, Benjamin Martin Wolf Aug 2019

Diverse Far-Red Light Utilization Strategies In Cyanobacteria And Algae, Benjamin Martin Wolf

Arts & Sciences Electronic Theses and Dissertations

In their natural environments, photosynthetic organisms are often exposed to widely varied light environments. Species adapted to shade light, often found growing in lower layers of photosynthetic biofilms, must survive on filtered light alone. Filtered light is highly enriched in far-red wavelengths, which are normally unavailable for photosynthetic energy production in most oxygenic phototrophs. To overcome light limitations in filtered light environments, some species of algae and cyanobacteria utilize specialized photosynthetic pigments and antenna systems to harvest these far-red wavelengths. By sampling the natural environment and using custom-built far-red light growth chambers, I have isolated several species of oxygenic phototrophs …


The Mechanism Of Hyper Daptomycin Resistance In Corynebacterium Striatum And Daptomycinճ Mechanism Of Action, Nicholas Kevork Goldner Aug 2018

The Mechanism Of Hyper Daptomycin Resistance In Corynebacterium Striatum And Daptomycinճ Mechanism Of Action, Nicholas Kevork Goldner

Arts & Sciences Electronic Theses and Dissertations

Daptomycin, a last line-of-defense antibiotic for treating Gram-positive infections, is experiencing clinical failure against important infectious agents, including Corynebacterium striatum. The recent transition of daptomycin to generic antibiotic status is projected to dramatically increase availability, use, and clinical failure. Despite daptomycinճ more than 30-year history as an important antibiotic, four major questions were left unanswered. 1) How do bacteria become hyper-resistant to daptomycin? 2) What is the in vivo membrane target of daptomycin? 3) How does daptomycin interact with the membrane? 4) What is daptomycinճ mechanism of killing? These four questions have plagued the daptomycin field, and even now conflicting …


Type 1 And F17-Like Pili Promote The Establishment Of The Uropathogenic E. Coli Intestinal Reservoir, Caitlin Nicole Spaulding Aug 2017

Type 1 And F17-Like Pili Promote The Establishment Of The Uropathogenic E. Coli Intestinal Reservoir, Caitlin Nicole Spaulding

Arts & Sciences Electronic Theses and Dissertations

Urinary tract infections (UTI) affect over 150 million individuals worldwide every year. These infections are associated with significant morbidity and have a sizeable economic impact, with $5 billion being spent on UTI treatment in the USA annually. Uropathogenic E. coli (UPEC) are responsible for 80% of community acquired UTIs and 65% of nosocomial UTI. The current standard of care for UTI is antibiotic therapy. However, 30-50% of women experience recurrent UTI (rUTI) despite receiving antibiotic therapy. The prevalence of single and multi-drug resistant UPEC strains has led to increased reliance on carbepenems, which are primarily reserved for multi-drug resistant infections, …


Antiviral Nucleoside Inhibitors Of Leishmania Rna Virus 1: Discovery And Mechanism, John Isaac Robinson Aug 2017

Antiviral Nucleoside Inhibitors Of Leishmania Rna Virus 1: Discovery And Mechanism, John Isaac Robinson

Arts & Sciences Electronic Theses and Dissertations

Some Leishmania parasites in the Viannia sub-genus are persistently infected with Leishmania RNA virus 1 (LRV1), a single-segmented double-stranded RNA virus belonging to the family Totiviridae. Infected parasites cause greater pathology and reach higher populations in mouse models of Leishmania infection. In human disease, LRV1+ parasites are correlated with increased frequency of treatment failure and relapse. Efficient methods to detect LRV1 and eliminate it from parasites are required to better understand the role of LRV1 in Leishmania infection. We optimized multiple techniques to measure LRV1 levels in parasites, most notably using flow cytometry to measure the amount of viral capsid …


Metal Selectivity And Acquisition By The Yersiniabactin Metallophore System In Escherichia Coli, Eun-Ik Koh May 2016

Metal Selectivity And Acquisition By The Yersiniabactin Metallophore System In Escherichia Coli, Eun-Ik Koh

Arts & Sciences Electronic Theses and Dissertations

Urinary tract infections (UTI) are one of the most common bacterial infections, of which, the majority are caused by uropathogenic Escherichia coli (UPEC). Many bacterial pathogens including UPEC synthesize and secrete chemically diverse metabolites called siderophores, which are classically defined by their ability of bind and deliver iron(III), an essential nutrient, to pathogens during infections. UPEC isolates can express multiple siderophore systems, of which, the virulence-associated siderophore yersiniabactin (Ybt) binds to both iron(III) and copper(II) during urinary tract infections. In this thesis we show that Ybt interacts with multiple physiologic transition metals and acts as a metallophore system to deliver …