Biochemistry, Biophysics, and Structural Biology Commons^™

Structural Integrity And Stability Of Dna In Ionic Liquid And Near-Infrared Indolizine Squaraine Dye, Ember Yeji Suh

Honors Theses

Luminol, the most common presumptive test for blood at a crime scene, has multiple issues, such as false positive results with chemical agents, no luminescence due to “active oxygen” cleaning agents on bloodstains, and inability to penetrate textile materials. A combination of indolizine squaraine dye and ionic liquid (IL), or Dye Enhanced Textile Emission for Crime Tracking (DETECT), have shown potential to address these issues. The purpose of this study was to assess the binding mechanism of CG (1:1) and SO₃SQ dye to HSA and how the mechanism can explain the W214 fluorescence quenching effect and to determine …

Photocatalyzed Hydrogen Evolution Using Nickel-Bound Metallothionein Protein, Windfield Swetman

Honors Theses

The continued burning of fossil fuels is not only a cause of increasing deterioration of the environment but also a financially unsustainable source of energy. Advances in energy production must be investigated to avoid the long-term effects of this current main source of energy. One of the avenues being explored is the use of metalloenzymes to catalyze hydrogen evolution via water splitting that occurs during the reductive half of artificial photosynthesis. Metalloenzyme catalysts with a single Ni(Cys)₄ active site have been previously studied, and this study explores the possibility of increasing hydrogen production by using metalloenzyme catalysts with multiple …

Copper Chelation Via Beta-Alanine Extends Lifespan In A C. Elegans Model Of Alzheimer’S Disease, Arnulfo Pulido, Benjamin Hulbert, Hayleigh Giese, Sabrina Kurian, Rebbeca Rozhon, Michael Zambrano, Oscar Diaz, Mariam Abd, Madison Caputo, Daniel S. Kissel, Mallory A. Havens

Biology Department Faculty Articles

The leading hypothesis for Alzheimer’s Disease (AD) has traditionally focused on the aggregation of Amyloid-β into amyloid plaques. However, research has yet to definitively prove the role of the amyloid peptide in the pathology of the disease. Given that all therapeutics targeting amyloid plaques have failed in clinical trials, with one exception, there is a need to explore alternative approaches to treatment of this disease. Therefore, we examined other factors that are altered during AD pathogenesis. Many AD patients have dysregulation of metal ions, such as copper and zinc, in addition to accumulation of Amyloid-β. The interaction between Amyloid-β and …

Antimicrobial Activity And Mechanism Of Amyloid Proteins And Synthetic Conjugated Polyelectrolytes, Fahimeh Maghsoodi

Nanoscience and Microsystems ETDs

Although the exact cause of Alzheimer’s disease (AD) is still unknown, it is widely considered that the accumulation of amyloid plaques composed of the amyloid-β (Aβ) peptide in the brain is linked to neurodegeneration. Co-localization of viral DNA with Aβ plaques, the association of brain infection and AD, and research indicating the protective effect of Aβ against bacteria and fungi in mice and human cells have led to the hypothesis that Aβ expression and deposition may be central to its function as an antimicrobial peptide (AMP). In my thesis research, we seek to elucidate how Aβ functions as an AMP …

Structure Of A Eukaryotic Cholinephosphotransferase-1 Reveals Mechanisms Of Substrate Recognition And Catalysis, Lie Wang, Ming Zhou

Faculty, Staff and Students Publications

Phosphatidylcholine (PC) is the most abundant phospholipid in eukaryotic cell membranes. In eukaryotes, two highly homologous enzymes, cholinephosphotransferase-1 (CHPT1) and choline/ethanolamine phosphotransferase-1 (CEPT1) catalyze the final step of de novo PC synthesis. CHPT1/CEPT1 joins two substrates, cytidine diphosphate-choline (CDP-choline) and diacylglycerol (DAG), to produce PC, and Mg2+ is required for the reaction. However, mechanisms of substrate recognition and catalysis remain unresolved. Here we report structures of a CHPT1 from Xenopus laevis (xlCHPT1) determined by cryo-electron microscopy to an overall resolution of ~3.2 Å. xlCHPT1 forms a homodimer, and each protomer has 10 transmembrane helices (TMs). The first 6 TMs carve …

Topical Administration Of An Apoptosis Inducer Mitigates Bleomycin-Induced Skin Fibrosis, Md Nurul Huda, Edgar A Borrego, Cristina D Guerena, Armando Varela-Ramirez, Renato J Aguilera, Christine M Hamadani, Eden E L Tanner, Abu Zayed Md Badruddoza, Sandeep K Agarwal, Md Nurunnabi

Faculty, Staff and Students Publications

Pathological fibrosis is distinguished from physiological wound healing by persistent myofibroblast activation, suggesting that therapies that induce myofibroblast apoptosis selectively could prevent progression and potentially reverse the established fibrosis, such as for scleroderma (a heterogeneous autoimmune disease characterized by multiorgan fibrosis). Navitoclax (NAVI) is a BCL-2/BCL-xL inhibitor with antifibrotic properties and has been investigated as a potential therapeutic for fibrosis. NAVI makes myofibroblasts particularly vulnerable to apoptosis. However, despite NAVI's significant potency, clinical translation of BCL-2 inhibitors, NAVI in this case, is hindered due to the risk of thrombocytopenia. Therefore, in this work, we utilized a newly developed ionic liquid …

Physiological And Proteomic Analysis Of Soybean In Response To Drought And Heat Stress, Amandeep Kaur

Theses and Dissertations

Drought and temperature stress are the two most important factors limiting crop productivity. A physiological and proteomic analysis of soybean was performed to investigate the negative impact of these variables. The previous studies reported the beneficial effect of silicon under stress conditions. Silicon supplementation may promote plant growth under drought stress, although the mechanism to alleviate drought stress is uncertain. The proteomic analysis of chloroplast proteins was carried out to study the response of silicon supplementation under drought stress.

Similarly, temperature stress, mainly heat stress, has an adverse effect on soybean plants. The comparative analysis of two soybean cultivars, DS25-1 …

All The Rage: Assessing The Age/Rage Signaling Pathway’S Effects On Healthspan And The Physiological Processes Of Aging, Brandon Ashmore

Honors Theses

Advanced glycation end products (AGEs) are protein, lipid, or nucleotide molecules that have been combined with sugars through nonenzymatic, irreversible glycation and oxidation reactions. Their accumulation in the body has been associated with the natural aging process and a wide range of pathologies, including chronic inflammation, sustained oxidative stress, diabetes, neurodegenerative diseases, atherosclerosis, and cancer. Their interaction with the receptor for advanced glycation end products (RAGE) has been linked to several proinflammatory signaling pathways associated with neurotoxicity and vascular lesions. While some research has been done on the possible health benefits of RAGE inhibition to extend lifespan, our study hopes …

Du Undergraduate Showcase: Research, Scholarship, And Creative Works, Caitlyn Aldersea, Justin Bravo, Sam Allen, Anna Block, Connor Block, Emma Buechler, Maria De Los Angeles Bustillos, Arianna Carlson, William Christensen, Olivia Kachulis, Noah Craver, Kate Dillon, Muskan Fatima, Angel Fernandes, Emma Finch, Colleen Cassidy, Amy Fishman, Andrea Francis, Stacia Fritz, Simran Gill, Emma Gries, Rylie Hansen, Shannon Powers, Jacqueline Martinez, Zachary Harker, Ashley Hasty, Mykaela Tanino-Springsteen, Kathleen Hopps, Adelaide Kerenick, Colin Kleckner, Ci Koehring, Elijah Kruger, Braden Krumholz, Maddie Leake, Lyneé Alves, Seraphina Loukas, Yatzari Lozano Vazquez, Haley Maki, Emily Martinez, Sierra Mckinney, Audrey Mitchell, Kipling Newman, Audrey Ng, Megan Lucyshyn, Andrew Nguyen, Stevie Ostman, Casandra Pearson, Alexandra Penney, Julia Gielczynski, Tyler Ball, Anna Rini, Christina Rorres, Simon Ruland, Helayna Schafer, Emma Sellers, Sarah Schuller, Claire Shaver, Kevin Summers, Isabella Shaw, Madison Sinar, Claudia Pena, Apshara Siwakoti, Carter Sorensen, Madi Sousa, Anna Sparling, Alexandra Revier, Brandon Thierry, Dylan Tyree, Maggie Williams, Lauren Wols

DU Undergraduate Research Journal Archive

DU Undergraduate Showcase: Research, Scholarship, and Creative Works

De Novo Design Of Artificial Cu Peptide For Substrate Oxidation And An Electrochemical Approach To Determine Reorganization Energy, Morgan Murphy

Honors Theses

Copper enzymes are found in nature. Their mechanisms and properties are unknown, as spectroscopy is limited. By creating artificially designed copper peptides through de novo design, the behavior, characteristics, and spectroscopy of copper enzymes can be studied to enhance understanding of the mechanisms involved with enzyme catalysis. Design, synthesis, purification, and characterization are completed to create a quality peptide mutant that can be studied to learn about natural enzymes. This plays an important role in pharmaceutical research, renewable energy sourcing, and studies of biological processes in the body. In this study, 3SCC de novo peptide is mutated at different positions, …

Effects Of Group Ii Metal Binding On The Stability Of Dna I-Motif Structures, Charlotte Powers

Honors Theses

B-form DNA can adopt alternative structures while in superhelical duress. Alternative DNA structures are favored when there is an asymmetric distribution on complementary DNA strands. Cytosine rich strands may utilize cytosine-cytosine base pairing to form a four-stranded structure known as the i-motif (iM). The stability of iMs is affected by several factors such as DNA sequence, temperature, pH, ionic strength of the solution, and crowded conditions. While the effects of temperature, pH, and crowding conditions on iM stability have been well documented, the effects of ion presence in a solution has been less studied. Hence, those studies are the basis …

Sensor-Controlled Digital Game For Heart Failure Self-Management: Protocol For A Randomized Controlled Trial, Kavita Radhakrishnan, Christine Julien, Matthew O'Hair, Rachel Tunis, Grace Lee, Angelica Rangel, James Custer, Tom Baranowski, Paul J Rathouz, Miyong T Kim

Faculty, Staff and Students Publications

BACKGROUND: Heart failure (HF) is the leading cause of hospitalization among older adults in the United States. There are substantial racial and geographic disparities in HF outcomes, with patients living in southern US states having a mortality rate 69% higher than the national average. Self-management behaviors, particularly daily weight monitoring and physical activity, are extremely important in improving HF outcomes; however, patients typically have particularly low adherence to these behaviors. With the rise of digital technologies to improve health outcomes and motivate health behaviors, sensor-controlled digital games (SCDGs) have become a promising approach. SCDGs, which leverage sensor-connected technologies, offer the …

Exrna-Eclip Intersection Analysis Reveals A Map Of Extracellular Rna Binding Proteins And Associated Rnas Across Major Human Biofluids And Carriers, Emily L Laplante, Alessandra Stürchler, Robert Fullem, David Chen, Anne C Starner, Emmanuel Esquivel, Eric Alsop, Andrew R Jackson, Ionita Ghiran, Getulio Pereira, Joel Rozowsky, Justin Chang, Mark B Gerstein, Roger P Alexander, Matthew E Roth, Jeffrey L Franklin, Robert J Coffey, Robert L Raffai, Isabelle M Mansuy, Stavros Stavrakis, Andrew J Demello, Louise C Laurent, Yi-Ting Wang, Chia-Feng Tsai, Tao Liu, Jennifer Jones, Kendall Van Keuren-Jensen, Eric Van Nostrand, Bogdan Mateescu, Aleksandar Milosavljevic

Faculty, Staff and Students Publications

Although the role of RNA binding proteins (RBPs) in extracellular RNA (exRNA) biology is well established, their exRNA cargo and distribution across biofluids are largely unknown. To address this gap, we extend the exRNA Atlas resource by mapping exRNAs carried by extracellular RBPs (exRBPs). This map was developed through an integrative analysis of ENCODE enhanced crosslinking and immunoprecipitation (eCLIP) data (150 RBPs) and human exRNA profiles (6,930 samples). Computational analysis and experimental validation identified exRBPs in plasma, serum, saliva, urine, cerebrospinal fluid, and cell-culture-conditioned medium. exRBPs carry exRNA transcripts from small non-coding RNA biotypes, including microRNA (miRNA), piRNA, tRNA, small …

Exploring The Interaction Of Minor-Groove-Binder Netropsin With Dna Using Optical Tweezers, Irbazhusain Shaikh

Honors Program Theses and Projects

Netropsin is an antibiotic that binds in the minor grooves of DNA, which also exhibits anticancer properties. There have been many previous studies that explored the binding of this drug to DNA using traditional methods where an ensemble averaging is used. In this study we explore the interaction of Netropsin with DNA at a single molecule level using dual beam optical tweezers. We trapped and stretched a single DNA molecule using optical tweezers to measure the force experienced by the DNA as a function of extension in the absence and presence of various concentrations of Netropsin. Our results show the …

Dna Supercoiling-Induced Shapes Alter Minicircle Hydrodynamic Properties, Radost Waszkiewicz, Maduni Ranasinghe, Jonathan M Fogg, Daniel J Catanese, Maria L Ekiel-Jeżewska, Maciej Lisicki, Borries Demeler, Lynn Zechiedrich, Piotr Szymczak

Faculty, Staff and Students Publications

DNA in cells is organized in negatively supercoiled loops. The resulting torsional and bending strain allows DNA to adopt a surprisingly wide variety of 3-D shapes. This interplay between negative supercoiling, looping, and shape influences how DNA is stored, replicated, transcribed, repaired, and likely every other aspect of DNA activity. To understand the consequences of negative supercoiling and curvature on the hydrodynamic properties of DNA, we submitted 336 bp and 672 bp DNA minicircles to analytical ultracentrifugation (AUC). We found that the diffusion coefficient, sedimentation coefficient, and the DNA hydrodynamic radius strongly depended on circularity, loop length, and degree of …

Elucidating The Impact Of Sos-Response Timing In On Escherichia Coli Survival Following Treatment With Fluoroquinolone Topoisomerase Inhibitors, Stephanie Schofield

Honors Scholar Theses

Antibiotic treatment failure is a public health crisis, with a 2019 report stating that roughly 35,000 deaths occur in the United States yearly due to bacterial infections that are unresponsive to antibiotics (1). One complication in the treatment of bacterial infection is antibiotic persistence which further compromises our battle to effectively treat infection. Bacterial persisters can exist in clonal bacterial cultures and can tolerate antibiotic treatment by undergoing reversible phenotypic changes. They can survive drug concentrations that their genetically identical kin cannot. Some persisters remain in a slow growing state and are difficult to target with current antibiotics. A specific …

Creation Of Tatde Rlnps For The Excision Of Integrated Hiv-1 Proviral Dna, Mahmudul Hasan

Theses & Dissertations

The persistence of integrated human immunodeficiency virus type 1 (HIV-1) proviral DNA despite combination antiretroviral therapy (ART) is the principal challenge to eliminating HIV-1 infection. This is made ever more complex based on the high viral mutation rates, diversity and resistance profiles. Taken together, these factors present principal obstacles towards any means to eliminate the virus from its infective human host. To address these factors, we have developed and validated a TatDE rLNP RNA delivery system. The system utilizes Clustered Regularly Interspaced Short Palindromic Repeat (CRISPR) guide RNAs (gRNAs) to target multiple exons of an integrated proviral HIV-1 (tat_{1-2 …}

A Critical Assessment Of The Role Of Clpxp-Mediated Proteolysis In The Development And Differentiation Of Chlamydia Trachomatis, Nicholas A. Wood

Theses & Dissertations

Chlamydia trachomatis, an obligate intracellular human pathogen, is the etiological agent of the most commonly reported bacterial sexually transmitted infection and the leading cause of preventable infectious blindness worldwide. In adapting to an intracellular niche, Chlamydia has evolved to eliminate superfluous genes from its chromosome. Despite its highly reduced genome, Chlamydia undergoes a complex developmental cycle in which the bacteria differentiate between two functionally and morphologically distinct forms: the infectious, non-replicative elementary body (EB) and the non-infectious, replicative reticulate body (RB). An EB initiates infection by binding to and inducing uptake into a host cell. Within the cell, the EB …

Examining The Ph Switch Of Copper-Zinc Superoxide Dismutase Mutant A4v, Ty Jungman

Honors Program Theses and Research Projects

Amyotrophic lateral sclerosis(ALS) is a neurodegenerative disease that causes progressive loss to motor neurons. Buildup of superoxide anions (O2-) and aggregation of superoxide dismutase (SOD) is thought to be probable causes of damage to the neurons. This damage results in the progressive loss of function in the neurons resulting in flaccid paralysis. Superoxide anions were originally thought to cause irreparable damage to the motor neurons; however, recent studies have shown that the aggregation of SOD causes damage to the cell. Furthermore, the ability for the SOD1 to get metalated to dissuade aggregation has become an important topic of study in …

The Involvement Of Ubiquitin In Med13 Cyclin C Degradation Following Cellular Stress, Ayesha Gurnani, Brittany Friedson, Katrina Cooper

Rowan-Virtua Research Day

The Cdk8 Kinase Module is a dissociable regulator of cellular stress response genes, with degradation of its components Med13 and cyclin C eventually determining cell fate decisions such as engaging cell survival or cell death mechanisms. We aimed to explore the roles of ubiquitin in degradation of the Cdk8 Kinase Module following nitrogen starvation, with respect to the potential involvement of deubiquitinating enzyme Doa4, lysine linkage at position K63, and E2 ubiquitin conjugating enzymes Ubc4 and Ubc5. We utilized Western blot analysis to observe nitrogen starvation-induced degradation of Med13-HA in wild-type, doa4 mutant, and K63R yeast strains; degradation of cyclin …