Biochemistry Commons^™

The Importance Of Ile716 Toward The Mutagenicity Of 8-Oxo-2’-Deoxyguanosine With Bacillus Fragment Dna Polymerase, Michelle L. Hamm, Anarosa A. Garcia, Rachel Gilbert, Manavi Johri, Miranda Ricart, Samantha L. Sholes, Laura A. Murray-Nerger, Eugene Y. Wu

Biology Faculty Publications

8-oxo-2’-deoxyguanosine (OdG) is a prominent DNA lesion that can direct the incorporation of dCTP or dATP during replication. As the latter reaction can lead to mutation, the ratio of dCTP/dATP incorporation can significantly affect the mutagenic potential of OdG. Previous work with the A-family polymerase BF and seven analogues of OdG identified a major groove amino acid, Ile716, which likely influences the dCTP/dATP incorporation ratio opposite OdG. To further probe the importance of this amino acid, dCTP and dATP incorporations opposite the same seven analogues were tested with two BF mutants, I716M and I716A. Results from these studies support the …

Alternative Polyadenylation Modulates Expression Of Pro-Fibrotic Proteins And Contributes To Lung Fibrosis, Junsuk Ko

Dissertations and Theses (Open Access)

Idiopathic pulmonary fibrosis (IPF) is a chronic lung disease which affects about 5 to 8 million individuals in the world. Despite the high prevalence, there is currently no cure for IPF, and the cause of this disease is still unclear. Our laboratory and collaborators have shown that nudix hydrolase 21 (NUDT21, which is also known as cleavage factor 25, CFIm25) is a key regulator of alternative polyadenylation (APA). NUDT21 depletion causes 3’UTR shortening via APA leading to enhanced mRNA stability and protein translation. This NUDT21 reduction promotes tumor growth in glioblastoma by enhancing expression of oncogenes. Cancer and IPF share …

Loss Of Caspase-8 Function In Combination With Smac Mimetic Treatment Sensitizes Head And Neck Squamous Carcinoma To Radiation Through Induction Of Necroptosis., Burak Uzunparmak

Dissertations and Theses (Open Access)

Caspase-8 (CASP8) is one of the most frequently mutated genes in Head and Neck Squamous Carcinomas (HNSCC), and mutations of CASP8 are associated with poor overall survival. The distribution of these mutations in HNSCC suggests that they are likely to be inactivating. Inhibition of CASP8 has been reported to sensitize cancer cells to necroptosis, a unique cell death mechanism. Here, we evaluated how CASP8 regulates necroptosis in HSNCC using cell line models and syngeneic mouse xenografts. In vitro, knockdown of CASP8 rendered HNSCCs susceptible to necroptosis induced by a second mitochondria-derived activator of caspase (SMAC) mimetic, Birinapant, when combined …

Electrophysiological Characterization Of The Inhibitory Effects Of 2-Amino-4-Bis (Aryloxy Benzyl) Amino Butanoic Acids On Alanine Serine Cysteine Transporter 2 And Sodium Coupled Neutral Amino Acid Transporter 2, Paul Serguei Zakrepine

Undergraduate Honors Theses

Alanine Serine Cysteine Transporter 2 (ASCT2) is a member of the solute carrier 1A (SLC1A) family of transport proteins. It is a Na+ dependent, obligatory neutral amino acid exchanger with the capability to transport glutamine and it is a primary glutamine transport protein in cancer cells. This glutamine transport capability confers an important physiological role for ASCT2 in the maintenance of intracellular amino acid pools for various metabolic and cell signaling pathways. Because of this, ASCT2 is found to be overexpressed in many cancers, which rely heavily on glutamine as an essential nutrient for cell survival and growth. A wealth …

Effect Of Ph And Lipid Composition On Membrane-Spanning Helices With Glutamic Acid Examined By Solid-State Nmr, Kelsey Marr

Chemistry & Biochemistry Undergraduate Honors Theses

Transmembrane proteins constitute about 30% of the proteins in a mammalian cell and are involved in major biological processes. The dynamic properties of membrane proteins and the ionization states of particular side chains are important for biological function. The biophysical properties of membrane proteins nevertheless can be difficult to decode, particularly for glutamic acid in the lipid environment of cell membranes. To study the ionization of glutamic acid in transmembrane peptides, guest glutamic acid residues were substituted into the well-defined model helix of GWALP23 (acetyl-GGAL4WLALALALALAL16ALWLAGA-amide). These guest residues were placed at position L16 or L4 and specific 2H-labeled alanine residues …

Therapeutic Drug Monitoring Of Apixaban Using Chromogenic Kits, Brooke Vogel

Undergraduate Honors Theses

Apixaban is a novel oral anticoagulant that prevents clotting by directly inhibiting Factor Xa in the coagulation cascade. Due to its different pharmacokinetics, previous standards for testing anticoagulant concentrations are ineffective at measuring apixaban. In this study, Hyphen Biomed Biophen Direct Xa Inhibitor and Biophen Heparin chromogenic kits from Aniara Diagnostica were used along with a NanoDrop™ One/One^C Microvolume UV-Vis Spectrophotometer to see if either of these kits provide acceptable precision and accuracy for the quantification of apixaban in plasma samples, as well as if there is a significant difference in these two kits at varying concentrations of apixaban. …

Reversible Inhibition Of Mycobacterial Dnab Protein Splicing By Zinc, Gabrielle Hardison

Honors College Theses

Inteins are emerging as post-translational regulatory elements, undergoing conditional protein splicing in response to a variety of environmental cues. Inteins are seamlessly removed by self-splicing from exteins, or flanking portions of the host protein, which they interrupt. DnaB of Mycobacterium smegmatis, a helicase essential for replication, harbors two inteins known as DnaBi1 and DnaBi2, each with discrete structural characteristics and insertion positions. DnaBi1 was used here to design a reporter system which links splicing with resistance to the antibiotic kanamycin. We built a construct that strictly requires catalytically active DnaBi1 for survival in the presence of kanamycin and used …

Innovative Biological Solutions For Nitrogen Fixation, Mathangi Soundararajan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Nitrogen is an important part of biological molecules like proteins and DNA and hence is essential for life as we know it. The most commonly found form of nitrogen is dinitrogen gas (N₂) in the atmosphere, which is not accessible to most organisms. Conversion of N₂ into a usable form (ammonia), occurs through an energy-demanding reaction called nitrogen fixation. As we think about sending humans to Mars, there is a need to develop technologies for nitrogen fixation to produce fertilizer and other valuable compounds to support life in those harsh conditions.

The Haber-Bosch process is used in …

Characterization Of Beryllium Ion Complexation In The Presence Of Biological Buffers Using Isothermal Titration Calorimetry, Guillermo Alexander Ramirez

UNLV Theses, Dissertations, Professional Papers, and Capstones

Be2+ ion is a biologically active metal that is capable of binding to proteins and has been shown to affect various cellular processes. When treated with Be2+, certain cancer cells display cytostatic effects. GSK3β is a regulatory kinase involved in the β-catenin pathway that may be involved in producing these cytostatic effects when Be2+ binds to it. In order to determine binding parameters between Be2+ and GSK3β, isothermal titration calorimetry (ITC) can be utilized. However, titrations at physiological pH cannot be carried out due to Be2+ unique speciation at neutral pH ranges. Significant precipitation occurs at pH 6 and higher …

Investigating The Mechanisms Responsible For Cephalosporin Resistance In Clostridioides Difficile Strain 630, Lara Anna Turello

UNLV Theses, Dissertations, Professional Papers, and Capstones

Clostridioides difficile infection (CDI) is one of the most common nosocomial infections worldwide. A major risk factor for CDI is antibiotic therapy, due to C. difficile’s resistance to a myriad of antibiotics—one of which are cephalosporins. Cephalosporins are ß-lactam antibiotics that function by binding to the active site of penicillin-binding proteins (PBPs), thus inhibiting peptidoglycan synthesis and leading to cell lysis. Gram-positive bacteria can counteract ß-lactams by (i) producing ß-lactamases, (ii) expressing modified PBPs, or (iii) by expressing efflux pumps.

Genomic analysis of C. difficile strain 630 revealed the presence of at least 31 putative ß-lactam resistance genes that encode …

Utilizing Breathing Techniques To Maximize Training Performance, Peyton Cater

UNLV Theses, Dissertations, Professional Papers, and Capstones

Anaerobic exercise causes metabolic acidosis to occur in the muscle, which is unfavorable for sustaining high intensity activity, as fatigue starts to set in. In order to compensate for the onset of fatigue produced by an acidic environment, respiratory alkalosis, induced by hyperventilation, can be performed to mitigate these effects. In contrast, research has shown that slowing down the breath rate, such as a two second inhale and three second exhale, has led to an increase in performance outcomes. Purpose: To investigate power output and the physiological responses after implementation of different breathing techniques during the recovery periods of intermittent …

The Retinoblastoma Protein Mediates Metabolic Reprogramming In Lung Cancer., Lindsey R. Conroy

Electronic Theses and Dissertations

Lung cancer is among the most frequently diagnosed cancers and is the leading cause of cancer-related deaths worldwide. One of the hallmark events in lung cancer pathogenesis is deregulation of the cell cycle. The retinoblastoma protein (pRb) is a tumor suppressor that is deleted, mutated, or inactivated in most lung cancer cases. Canonically, pRb functions to regulate cell cycle progression by repressing the transcriptional activity of the E2F family of transcription factors, inhibiting S phase entry. Although the cell cycle functions of pRb have been well established, recent studies have highlighted a functional role for pRb in controlling cellular metabolism. …

Effect Of Charged Lipids On The Ionization Behavior Of Glutamic Acid Containing Transmembrane Helices, Brooke Nunn

Chemistry & Biochemistry Undergraduate Honors Theses

Transmembrane proteins make up critical components of living cells. Protein function can be greatly impacted by the charged state of its respective components, the side chains of amino acid residues. Thus far, in the lipid membrane, little is known about the properties of residues such as glutamic acid. To explore these properties, I have included glutamic acid in a suitable model peptide-lipid system for fundamental biophysical experiments. Within the system, I have placed a glutamic acid residue instead of leucine in the L14 position of the helical hydrophobic peptide GWALP23 (acetyl-GGALWLALALALAL¹⁴ALALWLAGA-amide). Substitutions of glutamine and aspartic acid serve …

Antioxidating Effect Of Ampelocissus Sp. (Isi Nyaru) On Streptozotocin-Induced Diabetic Rats, Zamri Elly Zulaikha

Student Works (2020-2029)

The Ampelocissus sp. locally known as Isi Nyaru has been traditionally used by native Malaysian for medical purpose. The tuber was extracted with hexane, petroleum-ether, chloroform, methanol and water solvents. The seperation and detection of bioactive compounds were done using Thin Layer Chromatography (TLC) and Gas Chromatography Mass Spectrometry (GCMS) methods. The TLC results showed the presence of phenolic acids, flavonoids and terpenoids. While in GCMS has revealed the presence of hydrocarbon groups such as alkene, ester and ether, amino acid groups, dicarboxylic acid and cyclic aromatic compound. The total phenol content and total flavonoid content were highest in methanolic …

Investigating The Interactions Between Individual Calmodulin And Hiv-1 Protein Domains, Riley K. Kendall, Jerry Larue

Student Scholar Symposium Abstracts and Posters

The World Health Organization found that 37.9 million people were living with HIV by the end of 2018. HIV is a virus that weakens the immune system through viral replication and the destruction of CD4⁺ T-cells, which are white blood cells that detect infection and make antibodies. A cure for HIV has not yet been discovered. HIV-1 contains a Gag polyprotein which regulates the stages of viral replication. Previous studies suggest that the myristoyl group of a matrix protein peptide found on the Gag polyprotein, MA, forms a complex with a calcium-binding, multifunctional regulatory protein called Calmodulin (CaM). CaM …

Antimicrobial Activity Of Extracts From The Leaves Of Marrubium Vulgare, Ashley Cravens

Undergraduate Theses

Natural products have served as powerful therapeutics against pathogenic bacteria since the golden age of antibiotics of the mid-20th century. In the United States, antibiotics are a key component of modern medicine and are one of the top written prescriptions every year. However, overuse and misuse of antibiotics has led to an increasing frequency of antibiotic-resistant infections. These infections are difficult and expensive to treat, often resulting in increased length of illness, hospital stays, and mortality rates. This demonstrates a clear need for novel antibiotics in for modern medicine. Murrubium vulgare (white horehound) is a shrub found in the Appalachia …

A Study Of The Antioxidant Versus Pro-Oxidant Nature Of The Amyloid Beta Peptide And An Analysis Of The Natural Products, Isorhamnetin And Narignenin, As Antioxidants, Kaylee Holmes

Honors Theses

Alzheimer’s disease is a neurodegenerative disorder with no cure. Due to the widespread effects of this disease, abundant research efforts have gone towards finding a cure. The amyloid beta (Ab) peptide has been shown to be a potential cause of the disease due to destructive effects on tissues that it can have both by itself and through reactive oxygen species (ROS) generation. This study was performed in order to assess the structural properties of Ab₄₂monomers, fibrils and oligomers, to assess the antioxidant versus pro-oxidant behavior of the Ab peptide, and to assess the antioxidant nature of the natural …

Mutagenesis Of Claudins To Probe In Vivo Interactions And Assemblies, Currey Zalman, Alex J. Vecchio

UCARE: Research Products

Paracellular transport of solutes and the control of the flow of molecules through the intracellular space in vertebrate epithelia is directed by tight junctions (TJs). Claudins form paracellular barriers and pores that determine tight junction permeability. This investigation attempts to explain the molecular bases for destruction and reconstruction of tight junctions within epithelial cells, occurring via both natural and disease-causing mechanisms. This interdisciplinary research is important in the advancement of our understanding of human biology and health, as different disruptions to epithelial tight junctions are hallmarks of many human diseases. The overall objective was to take previously made Claudin containing …

Meeting Radiation Dosimetry Capacity Requirements Of Population-Scale Exposures By Geostatistical Sampling., Peter K Rogan, Eliseos J Mucaki, Ruipeng Lu, Ben C Shirley, Edward Waller, Joan H M Knoll

Biochemistry Publications

BACKGROUND: Accurate radiation dose estimates are critical for determining eligibility for therapies by timely triaging of exposed individuals after large-scale radiation events. However, the universal assessment of a large population subjected to a nuclear spill incident or detonation is not feasible. Even with high-throughput dosimetry analysis, test volumes far exceed the capacities of first responders to measure radiation exposures directly, or to acquire and process samples for follow-on biodosimetry testing.

AIM: To significantly reduce data acquisition and processing requirements for triaging of treatment-eligible exposures in population-scale radiation incidents.

METHODS: Physical radiation plumes modelled nuclear detonation scenarios of simulated exposures at …

Methylation Of Salmonella Typhimurium Flagella Promotes Bacterial Adhesion And Host Cell Invasion, Julia A Horstmann, Michele Lunelli, Hélène Cazzola, Johannes Heidemann, Caroline Kühne, Pascal Steffen, Sandra Szefs, Claire Rossi, Ravi K Lokareddy, Chu Wang, Laurine Lemaire, Kelly T Hughes, Charlotte Uetrecht, Hartmut Schlüter, Guntram A Grassl, Theresia E B Stradal, Yannick Rossez, Michael Kolbe, Marc Erhardt

Department of Biochemistry and Molecular Biology Faculty Papers

The long external filament of bacterial flagella is composed of several thousand copies of a single protein, flagellin. Here, we explore the role played by lysine methylation of flagellin in Salmonella, which requires the methylase FliB. We show that both flagellins of Salmonella enterica serovar Typhimurium, FliC and FljB, are methylated at surface-exposed lysine residues by FliB. A Salmonella Typhimurium mutant deficient in flagellin methylation is outcompeted for gut colonization in a gastroenteritis mouse model, and methylation of flagellin promotes bacterial invasion of epithelial cells in vitro. Lysine methylation increases the surface hydrophobicity of flagellin, and enhances flagella-dependent adhesion of …