Biochemistry, Biophysics, and Structural Biology Commons^™

The Structure Of Pila From Acinetobacter Baumannii Ab5075 Suggests A Mechanism For Functional Specialization In Acinetobacter Type Iv Pili, Leslie A. Ronish, Erik Lillehoj, James K. Fields, Eric J. Sundberg, Kurt Piepenbrink

Department of Biochemistry: Faculty Publications

Type IV pili (T4P) are bacterial appendages composed of protein subunits, called pilins, noncovalently assembled into helical fibers. T4P are essential, in many bacterial species, for processes as diverse as twitching motility, natural competence, biofilm or microcolony formation, and host cell adhesion. The genes encoding type IV pili are found universally in the Gram-negative, aerobic, nonflagellated, and pathogenic coccobacillus Acinetobacter baumannii, but there is considerable variation in PilA, the major protein subunit, both in amino acid sequence and in glycosylation patterns. Here we report the X-ray crystal structure of PilA from AB5075, a recently characterized, highly virulent isolate, at …

Functional Characterization Of O-Acetyltransferase Wssi: Role In Bacterial Cellulose Acetylation Of Achromobacter Insuavis And Pseudomonas Fluorescens, Alysha Burnett

Theses and Dissertations (Comprehensive)

Cellulose biofilms consist of a community of bacterial cells encased in a self-produced matrix of polymers (e.g. exopolysaccharides, such as cellulose) that facilitate a firm adherence to surfaces. The acetylation (addition of an acetyl group on carbohydrates) is crucial in virulence; thereby in some cases allowing opportunistic bacteria to cause harmful diseases. Pertaining to this research, the wrinkly spreader (WS) genotype of Pseudomonas fluorescens colonizes the air-liquid interface on food, water sources and human tissue to form a robust biofilm with the ability to spread across surfaces. The composition of this biofilm largely consists of bacterial cellulose polymers …

Structural And Functional Analysis Of Three Upregulated Gene Products, Tde0626, Tde1701, And Tde2714 From Treponema Denticola During Biofilm Formation, Jonah Nechacov

Theses and Dissertations (Comprehensive)

The progression of human chronic periodontitis within periodontal disease has been often linked to the presence of key pathogens, such as the presence of Treponema denticola, a late colonizer found in the deepening pockets of the gingival sulcus. This pathogen, as well as its associates Porphyromonas gingivalis and Tannerella forsythia, are classified as the ‘red complex’ and exist in a mixed biofilm during infection. It is within this biofilm state that previous transcriptomic analysis revealed a total of 126 genes that had an increase in their expression by 1.5-fold or greater in T. denticola. Three of these …

Characterization Of The Microbial Phosphonate-Activating Pntc Enzymes, Kyle Rice

Theses and Dissertations (Comprehensive)

New strategies are urgently needed to combat infectious diseases in an era of rising antibiotic resistance. Furthermore, an emerging appreciation for the human microbiome’s role in maintaining health motivates discovery of species-specific antibiotics that minimally disrupt our native bacterial communities. Small molecule modifications to bacterial cell surfaces represent a potentially rich source of new targets for next generation antibiotics, as these molecules mediate virulence and evasion of the host immune response. Phosphocholine (PCho) is a rare cell surface modification that contributes to virulence, and modifications with phosphonates like 2-aminoethylphosphonate (AEP) are even more unusual and therefore provide opportunities for species- …

Expression, Purification, Functional Characterization And Crystallization Of Three Porphyromonas Gingivalis Gene Products, Katarina Mandic

Theses and Dissertations (Comprehensive)

Dental biofilms are coupled polymicrobial aggregates that have attached to solid surfaces in the oral cavity. These collections of microorganisms are known to cause periodontal diseases that commence as localized inflammation of the gingiva and if untreated, eventually lead to irreversible alveolar bone resorption and tooth loss. Porphyromonas gingivalis is one of three periodontal pathogens that make up the “Red Complex”; a bacterial consortium responsible for the production of polysaccharide-rich biofilms that are essential to the inception and progression of periodontal disease. The dysbiosis and destructive inflammation caused by these organisms propel a self-sustained feed-forward loop that perpetuates periodontal disease. …

Structural Investigation Of Bcsc: Insight Into Periplasmic Transport During Cellulose Export, William Scott, Joel T. Weadge

Theses and Dissertations (Comprehensive)

A biofilm can be defined by a community of microbes coexisting within a self-produced protective polymeric matrix. Exopolysaccharide (EPS) is a key component in biofilms and a contributor to their virulence and pathogenicity. The cellulose bacterial synthesis complex is one such EPS system that is found in many Enterobacteriaceae,including Escherichia coli and Salmonella spp., and is responsible for the production and secretion of the EPS cellulose. BcsC is the periplasmic protein responsible for the export of the exopolysaccharide cellulose and was the focus of this research. Sequence homology comparisons and structural predictions between BcsC, and the previously characterized alginate …

Characterizing Chromosomal Aberrations In Cells Deficient For Both Atm And Msh2, Yeliz Inalman

Dissertations and Theses

Ataxia telangiectasia mutated (ATM) and mutS homologue 2 (MSH2) are important DNA repair proteins that participate in DNA repair pathways to maintain genomic integrity. Mice deficient for ATM and MSH2 mice are viable. However, ATM^-/- mice show growth retardation, neurological defects, and spontaneous lymphomagenesis. MSH2^-/- mice suffer from aggressive lymphoid tumors between two to five months of age and have increased microsatellite instability, which predisposes MSH2^-/- mice to carcinomas. However, mice deficient in both ATM and MSH2 are unable to survive beyond postnatal day 21 (P21). The observed lethality in ATM^-/-MSH2^-/- mice may result …

The Dna Dependent Protein Kinase Catalytic Subunit Maintains Genomic Stability, Brandon Lee Sklavanitis

Graduate Research Theses & Dissertations

GBM is the most common CNS derived malignancy diagnosed each year. The median survival time to date is between 14.6 to 16.7 months for patients suffering from the disease. Clinical trials and research has yet to yield a breakthrough treatment. The invasive nature of GBM to surrounding tissue typically poses a challenge for complete surgical resection of the tumor, and radiotherapy remains a predominant treatment modality. The NHEJ pathway is main repair pathway responsible for repairing lethal radiation damage. As a result, this study used the CRISPR-Cas9 system to genetically engineer two GBM cell lines lacking expression of an essential …

Comparative Tumorigenic Amino Acid Starvation And Integrated Stress Responses In Epithelial Vs. Mesenchymal Hcc Cells With Asct2 Or Lat1 Transporter Knockouts, Stephanie Lois Cooper Woodin

Graduate Research Theses & Dissertations

The previously established roles of the amino acid glutamine have recently been expanded to include not only protein and nucleotide synthesis, as well as contributing significantly to energy production via mitochondrial hydrolysis of glutamine to glutamate, but also the role of this molecule in the reductive carboxylation of α-ketoglutarate resulting in carbon atoms used in cell membrane biosynthesis. Additionally, glutamine participates in maintaining glutathione homeostasis as well as regulation of anabolic signaling. Given its central role in anabolic processes, glutamine is preferentially transported into human cancer cells at a significant rate as compared to normal cells. This distinction has prompted …

Aligning Best Practices In Student Success And Career Preparedness: An Exploratory Study To Establish Pathways To Stem Careers For Undergraduate Minority Students, Kimberly D. Kendricks, Anthony A. Arment, K. V. Nedunuri, Cadance A. Lowell

Journal of Research in Technical Careers

Undergraduate minority retention and graduation rates in STEM disciplines is a nationally recognized challenge for workforce growth and diversification. The Benjamin Banneker Scholars Program (BBSP) was a five-year undergraduate study developed to increase minority student retention and graduation rates at an HBCU. The program structure utilized a family model as a vehicle to orient students to the demands of college. Program activities integrated best K-12 practices and workforce skillsets to increase academic preparedness and career readiness. Findings revealed that a familial atmosphere improved academic performance, increased undergraduate research, and generated positive perceptions of faculty mentoring. Retention rates among BBSP participants …

From The Laboratory To The Vineyard—Evolution Of The Measurement Of Grape Composition Using Nir Spectroscopy Towards High-Throughput Analysis, Aoife Power, Vi Khanh Truong, James Chapman, Daniel Cozzolino

Articles

Compared to traditional laboratory methods, spectroscopic techniques (e.g., near infrared, hyperspectralimaging)provideanalystswithaninnovativeandimprovedunderstandingofcomplex issuesbydeterminingseveralchemicalcompoundsandmetabolitesatonce,allowingforthecollection of the sample “fingerprint”. These techniques have the potential to deliver high-throughput options for the analysis of the chemical composition of grapes in the laboratory, the vineyard and before or during harvest, to provide better insights of the chemistry, nutrition and physiology of grapes. Faster computers, the development of software and portable easy to use spectrophotometers and data analytical methods allow for the development of innovative applications of these techniques for the analyses of grape composition.

Mapping The Effects Of 5’ Untranslated Region Deletions On Translation Of 3a In Bmv Rna3, Courtney Marie Bozman

Graduate Research Theses & Dissertations

Brome mosaic virus (BMV) is a positive sense, single-stranded RNA virus that infects a wide array of plant hosts globally including: wheat, oats, maize, barley, and rye. Since its discovery in the 1940s, BMV has served as a model organism in uncovering the modalities of viral infectivity, composition, translation, and replication. In many viruses, it is typically imperative to recruit cellular machinery to produce viral proteins as their coding capacity is limited. Therefore, there are sequences and structures within the leader sequences allow them to be competitive with the eukaryotic mRNAs. Although BMV has been thoroughly researched in these other …

Avoiding Adverse Effects: New Ideas In Drug Discovery For Targeting Pparγ, Trey M. Patton

Graduate Student Theses, Dissertations, & Professional Papers

Peroxisome proliferator-activated receptor gamma (PPARγ) has been a drug target to treat type 2 diabetes for the last 20 years when rosiglitazone and pioglitazone were approved by the FDA in 1999. While effective at increasing insulin sensitivity, these drugs cause serious adverse effects due to their full agonist characteristics. For that reason, drug discovery efforts have attempted to reduce or prevent the amount of agonist character of new PPARγ targeting ligands. Unfortunately, there have been no new FDA approved drugs for the receptor. There is a need for new ideas to produce better quality pharmaceuticals that lessen the impact of …

The Development Of A High-Throughput Screening Assay For Acetyl-Coa Carboxylase Using 1,3,6,8-Tetrahydroxynapthalene Synthase, Sarah Elayne Cohen

Honors Capstones

No abstract provided.

Tumor-Targeted Conjugated Polymer Nanoparticles With Encapsulated Iron And Its Biomedical Application For In Vitro Killing Of Melanoma Cell Lines Through Ferroptosis Assisted Chemodynamic Therapy (Cdt), Khalaf Jasim

Electronic Theses and Dissertations

Melanoma represents one of the most aggressive and lethal forms of skin cancer, with annually rising incidences throughout the world. Although chemotherapy modalities remain the mainstay of treatment, the therapeutic potential of chemotherapy typically is hampered by multidrug resistance (MDR) and nonspecific drug distribution that causes side-effects. To surmount such limitations, novel nanoformulations of low band-gap poly ({4,8-bis [(2-ethylhexyl) oxy] benzo [1,2-b:4,5-b?] dithiophene-2,6-diyl}{3-fluoro-2-[(2-ethylhexyl) carbonyl] thieno [3,4-b] thiophenediyl}) (PTB7) and poly [2,1,3-benzothiadiazole- 4,7- diyl [4,4-bis (2-ethylhexyl)- 4H-cyclopenta [2,1-b:3,4-b'] dithiophene-2,6-diyl]] (PCPDTBT) were fabricated by a reprecipitation method. These conjugated polymer nanoparticles were functionalized with the polypeptide endothelin-3 (EDN3-CPNPs) to target melanoma. The …

Investigation Of The Interactions Between The Dream Complex And Hpv16, Kevin Ko

Theses and Dissertations

According to the American Cancer Society, it has been estimated that in 2019 alone, there will be approximately 53,000 new cases of oropharyngeal cancers. Oropharyngeal cancers are the largest subset of head and neck squamous cell carcinomas (HNSCCs), which are the sixth most common cancer across worldwide populations. They, along with other HNSCCs, fall under a category of cancers known as Human papillomavirus (HPV)-associated cancers, and it has been found that upwards of 70% of these cancers can be attributed to high-risk HPV infections.

Specifically, the high-risk HPV gene, E7, plays a key role in relieving cell cycle repression by …

Studies Of Oxidative Damage, Brain Proteome, And Neurochemical Metabolites In Cognitive And Neurodegenerative Disorders: (1) Chemotherapy-Induced Cognitive Impairment; (2) Parkinson Disease Rat Model, Xiaojia Ren

Theses and Dissertations--Chemistry

The rate of cancer patients is increasing as the development of science and technology. Twenty million cancer survivors are estimated living in the United States by 2025. However, many cancer survivors show cognitive dysfunction, negatively affecting the quality of life. These cognitive impairments are recognized as chemotherapy-induced cognitive impairment (CICI), also called "chemo brain" by cancer survivors, including the diminished ability of memory and learning, hard to concentrate and focus, as well as diminution of executive function and processing speed. The etiologies and pathologies of CICI are complicated, especially in most cases the anti-cancer drug cannot cross the blood-brain barrier …

Investigation Of Amyloid Β Oligomer Dissociation Mechanisms By Single Molecule Fluorescence Techniques, Hope Cook Abdalla

Theses and Dissertations--Chemistry

Alzheimer’s disease (AD) is currently considered the most prevalent neurodegenerative disease and places a large financial burden on society as healthcare resources are limited and the disease does not have a cure. Alzheimer’s disease is characterized by the presence of amyloid beta (Aβ) plaques and neurofibrillary tangles; however current literature suggests Aβ oligomers are the main aggregating species leading to AD symptoms. Therefore, the underlying cause of Alzheimer’s, accumulation of amyloid beta, is currently being studied in hopes of developing treatment options. Our research aims at determining the mechanism and kinetics of Aβ oligomer dissociation into non-toxic monomers in the …

The Role Of Rmta In The Opportunistic Pathaogen Aspergillus Fumigatus, Roshan Dahal

Graduate Research Theses & Dissertations

The fungus Aspergillus fumigatus is an opportunistic human pathogen capable of causing

a life-threatening systemic lung infection known as invasive aspergillosis among immune compromised

patients. This group includes individuals infected with HIV, people with hematological

malignancies, solid organ transplant patients, persons with genetic immunodeficiency and cancer

patient undergoing chemotherapy. Due to the medical relevance of this organism, it is imperative

to discover novel genetic elements to design antifungal drugs against A. fumigatus dissemination,

virulence and survival during human infection. Previously, the putative arginine methyltransferase

gene rmtA was characterized in the model organism Aspergillus nidulans and the opportunistic

plant pathogen Aspergillus …

Hif-2 Regulation Of Amino Acid Transporter Expression In Hepatocellular Carcinoma Cells, Jason A. Misurelli

Graduate Research Theses & Dissertations

Hypoxia represents a major driver of the cancer phenotype in solid tumors, especially those of hepatic origin. Low oxygen availability triggers a complex cellular response which alters metabolism and promotes cellular invasion. Growing evidence suggests the amino acid glutamine, an important molecular currency for both energy producing reactions and biosynthetic pathways, plays an enhanced role in cancer cells under hypoxia. Hypoxia-inducible factors (HIFs) are transcription factors crucial for regulating the cellular response to low oxygen. Family member HIF-1 has been well studied, however, recent evidence suggests HIF-2 may have a regulatory role in amino acid transport and metabolism under hypoxia. …