Biochemistry, Biophysics, and Structural Biology Commons^™

Single-Molecule Orientation Imaging Reveals The Nano-Architecture Of Amyloid Fibrils Undergoing Growth And Decay, Brian Sun, Tianben Ding, Weiyan Zhou, Tara S. Porter, Matthew D. Lew

Electrical & Systems Engineering Publications and Presentations

Amyloid-beta (Aβ42) aggregates are characteristic Alzheimer’s disease signatures, but probing how their nanoscale architectures influence their growth and decay remains challenging using current technologies. Here, we apply time-lapse single-molecule orientation-localization microscopy (SMOLM) to measure the orientations and rotational “wobble” of Nile blue (NB) molecules transiently binding to Aβ42 fibrils. We correlate fibril architectures measured by SMOLM with their growth and decay over the course of 5 to 20 min visualized by single-molecule localization microscopy (SMLM). We discover that stable Aβ42 fibrils tend to be well-ordered and signified by well-aligned NB orientations and small wobble. SMOLM also shows that increasing order …

Modeling Hydroxide In Classical Proton Hopping Simulations And Amyloid Beta Membrane Pores, Ankita Dutta

Dissertations, Theses, and Capstone Projects

H3O+ and OH- ions display anomalously large diffusion coefficients, a property that is often attributed to their ability to perform structural diffusion which allow these ions to move through aqueous solutions by sequential proton transfers, also known as ‘Grotthuss hopping’. A rearrangement of the local solvation structure is known to be the prerequisite for proton transfer events via these ions. Studying this phenomenon using classical molecular dynamics simulations that do not allow bond rearrangements poses significant obstacles. Here we use a Monte Carlo augmented classical Molecular Dynamics method called the MOBHY algorithm which allows instantaneous changes in protonation states in …

Assessing The Pre- And Post-Synaptic Effects Of Opioids On Inspiratory Rhythmogenesis, Jingzhi Zhao, Diego Morandi Zerpa

Biology and Medicine Through Mathematics Conference

No abstract provided.

The Interactions Of Centromeric Nucleosomes Elucidated By Atomic Force Microscopy, Shaun Filliaux

Theses & Dissertations

Nucleosomes are the fundamental unit of compaction for DNA in the genome. These positively charged proteins have two main types of nucleosomes: canonical (H3 containing) and centromere (CENP-A containing). The compacting of DNA allows for DNA to fit into the nucleus of cells, but creates a barrier for DNA accessibility for operations such as replication or transcription. Centromeric chromatin is a subset of chromatin structure and governs chromosome segregation. Compared to the bulk chromosome, centromeres are composed of H3 and CENP-A nucleosomes in which H3 histones is replaced by its homolog CENP-A histone. This results in nucleosomes with different structures, …

Intrinsically Disordered Proteins And Their Role In Biomolecular Condensates, Danielle Latham

All Dissertations

Proteins are biomacromolecules responsible for the functions of life. While classically proteins are thought to be well structured in order to perform a specific function, 50% of proteins within Eukaryotic cells contain intrinsically disordered regions (IDRs), regions with no well-defined structure. IDRs are often used for cell signaling, responding to external factors such as temperature changes or the presence of small molecules. To understand how IDRs can function without structure, it is important to understand the dynamics of such systems. Understanding IDR intramolecular and intermolecular interactions will shed light on IDR dynamics. Intramolecular interactions are first explored using fluorescence spectroscopy …

Assessing Nordihydroguaiaretic Acid Properties And Its Potential Therapeutic Effect For Glioblastoma, Jose Arturo Guerrero

Open Access Theses & Dissertations

This study employs a combination of theoretical and experimental analysis to spectroscopically investigate the biomechanistic structure relationship and therapeutic effects of the Nordihydroguaiaretic Acid (NDGA) chemical derived from the Larrea Tridentata plant. These relationships are crucial for understanding NDGA's efficacy in disease prevention, treatment, and potential toxicological effects. While the medicinal and antiviral properties of the NDGA have been studied extensively, there remains a gap in optically identifying and reporting its structural changes. The current research successfully reveals evident trends in NDGA's vibrational signatures, particularly highlighting the absence of the Raman feature at 780 〖cm〗^(-1) as indicative of a fully …

An Investigation Into The Structural Features That Control Factor Xiii Stability And Substrate Specificity., Rameesa Darul Amne Syed Mohammed

Electronic Theses and Dissertations

Factor XIII (FXIII) is a transglutaminase enzyme with multiple physiological roles that is found in plasma and cells of bone marrow origin. The catalytic A subunit (FXIII-A) is made of an N-terminal activation peptide (AP), β-sandwich, catalytic core, and two β-barrel domains. FXIII crosslinks the sidechains of glutamine (Q) and lysine (K) residues across plasmatic and cellular substrates. Because of its involvement in clot stabilization and determining fibrin clot size, FXIII-A is regarded as a target for developing new anticoagulants with minimal bleeding risks. However, the FXIII-A structural features that control its stability and substrate specificity largely remain unknown. Plasma …

Coomassie Brilliant Blue Dye As A Method For Analyzing Fracture Markings In Bone, Abigail Hoffmeister, David Harutunyan, Matthew Aizawa, Everett Baker, Brandon Mendoza, Chase Freeman, Siran Iskanian

Seaver College Research And Scholarly Achievement Symposium

Coomassie Brilliant Blue Dye is a dye commonly used to stain proteins. Because of its ability to adhere to proteins, this research has focused on perfecting a method of dyeing a fractured flat bone in order to most accurately observe and analyze fracture markings within the trabecular layer. Stereoscopic microscopy was the chosen technique of analysis for this research because of its proven effectiveness in glass and ceramic fractography to observe varying depths. In order to most effectively apply stereoscopic microscopy to this research, the following variables were manipulated to maximize color contrast in the trabecular layer in order to …

Development Of An Integrated Workflow For Nucleosome Modeling And Simulations, Ran Sun

Doctoral Dissertations

Nucleosomes are the building blocks of eukaryotic genomes and thus fundamental to to all genetic processes. Any protein or drug that binds DNA must either cooperate or compete with nucleosomes. Given that a nucleosome contains 147 base pairs of DNA, there are approximately 4^147 or 10^88 possible sequences for a single nucleosome. Exhaustive studies are not possible. However, genome wide association studies can identify individual nucleosomes of interest to a specific mechanism, and today's supercomputers enable comparative simulation studies of 10s to 100s of nucleosomes. The goal of this thesis is to develop and present and end-to-end workflow that serves …

Identification Of Regulatory Elements In The Untranslated Regions Of Streptolysin S Associated Gene A Messenger Rna From Group A Streptococcus, Cameron R. Carroll, Sara G. Nibar, Alexis S. Brown, Lauren R. Angello, Gabriela C. Pérez-Alvarado, Brian M. Lee

Journal of the South Carolina Academy of Science

Streptococcus pyogenes, also known as group A Streptococcus (GAS), is a human pathogen associated with a variety of diseases such as strep throat, scarlet fever, toxic shock syndrome, and necrotizing fasciitis. One of the virulence factors released by GAS during an invasive infection is a cytotoxic peptide, streptolysin S (SLS), which inhibits the immune response to necrotizing fasciitis. The streptolysin S associated gene A product, SagA, is modified to produce SLS. Thesag operon includes sagA and the genes required for enzyme-mediated post-translational modifications of SagA and the export of SLS. The sagA gene is contained within the pleiotropic …

Detecting Interactions Between Mps3 In Linc Complex And Ndj1 In Nuclear Pore Complex In Mechanically Stressed Yeast, Dean Boecher, Rebecca Adams

[Archive] Belmont University Research Symposium (BURS)

The mechanisms of how mechanical stress is translated into cellular action and structural reorganization within the nuclear envelope are largely unexplored. The Linker of Nucleoskeleton and Cytoskeleton (LINC) complex is a transmembrane protein complex that connects the actin cytoskeleton to the lamin nucleoskeleton, enabling mechanical forces to be translated between the cytoplasm and the nucleus. A better understanding of the translation of physical forces into cell responses can be gained through confirming the existence of interactions between LINC complex proteins and nuclear pore complexes (NPCs), which control the exchange of biochemical signals and macromolecules in and out of the nucleus …

Mathematical Modeling Of Microscale Biology In Polyelectrolyte Brushes, William J. Ceely

CGU Theses & Dissertations

Biological macromolecules including nucleic acids, proteins, and glycosaminoglycans are typically anionic and can span domains of up to hundreds of nanometers and even micron length scales. The structures exist in crowded environments that are dominated by multivalent electrostatic interactions that can be modeled using mean-field continuum approaches that represent underlying molecular nanoscale biophysics. In this thesis, we develop such models for polyelectrolyte brushes using both steady state modified Poisson-Boltzmann models and transient modified Poisson-Nernst-Planck models that incorporate important ion-specific (Hofmeister) effects. The transient model enables observation of the relative physical effects as an initial non-equilibrium state relaxes to the steady …

Illuminating Function And Enabling Inhibition At The Protein-Membrane Interface Of Glutathione Peroxidase 4., Courtney L. Labrecque

Theses and Dissertations

Membrane proteins act as gateways to cells and are responsible not only for signaling, lipid transport, and cellular homeostasis, but they are also integral in disease pathologies. One class of membrane proteins, peripheral membrane proteins (PMPs), reside in aqueous compartments of the cell until they are recruited to the membrane to perform their function. Glutathione peroxidase 4 (GPx4) is a PMP enzyme responsible for engaging the membrane and reducing lipid hydroperoxides, thereby preventing cellular death via ferroptosis. Due to its central function surrounding ferroptosis, GPx4 is an interesting drug target that has recently gained interest for inflammatory diseases as well …

Compliance And Roughness In Relation To Gecko Locomotion, Brooklynn Campbell

Williams Honors College, Honors Research Projects

Geckos move efficiently through a variety of substrates, from swaying branches to wooden fences to the sides of structures. Previous studies have studied locomotion and adhesion on manmade and rough substrates; however, the work is limited when discussing locomotion and adhesion as a relationship of compliance and roughness. Ease of movement was quantified by speed, under the assumption that the faster a gecko moves, the easier it is for the gecko to cross the substrate. Gehyra oceanica geckos from Moorea, French Polynesia were tested on substrates varying in compliance and roughness with four different treatments in total. Compliance, roughness, and …

The Study Of Ribosome-Amplified Metabolism, Rambo, Effect In Vitro And In Live Cells, Jianchao Yu

Electronic Theses & Dissertations (2024 - present)

Quinary interactions arise due to the extreme macromolecular crowding inside live cells. Quinary interactions affect intracellular protein stability, activity, and homeostasis. Ribosomes, traditionally known for their role in protein synthesis, have been found to engage in quinary interactions with metabolic enzymes, modulating their activity and thereby revealing a potential regulatory role for ribosomes in cellular metabolism. This phenomenon, termed the Ribosome-Amplified MetaBOlism (RAMBO) effect, was investigated in this dissertation through a series of in vitro and in vivo studies using primarily Nuclear Magnetic Resonance (NMR) spectroscopy.

Firstly, an NMR-based direct enzyme assay compatible with ribosome was developed and validated using …

Transparent And Conductive Gallium Oxide Electrode For Simultaneous Recording And Optogenetic Stimulation, Christopher Patrick Carey

Graduate Theses, Dissertations, and Problem Reports (ETD)

Neural electrode technology has been around for centuries since the times of Galvani. In early electrophysiology experiments metal wires were used to induce contractions in dissected animals. The metal wire electrode has since been a standard tool to both stimulate and record neural activity. In the past two decades, a new strategy for neural stimulation has been formulated based on the emergent field of optogenetics. Optogenetics refers to the use of light-sensitive proteins genetically imbedded in the membrane of a neuron to elicit neural activity. This technique offers more selectivity in the stimulation of neurons. Typical optogenetic neural electrodes, or …

Investigating Dynamics Of Electron Transfer Flavoprotein And Its Partner Flavodoxin Via Small Angle Neutron Scattering And Fluorine Nmr, Sharique Ahmad Khan

Theses and Dissertations--Chemistry

Anaerobic bacteria and archaea thrive in seemingly inhospitable environments because they are extremely energy efficient. Their capacity to fully utilize electrochemical energy is based in large part on their ability to conduct electron transfer bifurcation ('bifurcation') at strongly reducing potentials, thereby producing extremely potent reducing agents able to fix nitrogen and make molecular hydrogen. This chemistry is made possible by the use of a flavin as the site of bifurcation, supported by a specialized protein environment and mechanisms that control the flow of individual electrons.

Bifurcating electron transfer flavoproteins (Bf-ETFs) are versatile protein modules that provide the bifurcating capability associated …

Dna I-Motifs: Biophysical Characterization And Structure-Property Correlation As Foundation For Functional Material Design, Alexander Minasyan

Graduate Research Theses & Dissertations

Over the past decades, nucleic acids have emerged as crucial frameworks with significance in biological systems and functional material engineering. Cytosine-rich deoxyribonucleotide sequences can form quadruplex structures a.k.a. i-motifs. Recently, i-motifs have attracted scientific interest in biological and material design areas.

In this work, we systematically investigate an effect of structured and unstructured modifications such as hairpins, stems, loops and overhangs on the kinetic and thermodynamic properties of DNA i-motifs. We demonstrate that the modifications can influence i-motif’s stability and folding/unfolding rates: thus, double stranded stems and hairpins are the best at stabilizing i-motifs and increasing kinetic rates of folding. …

Quantitative Raman Analysis Of Human Blood Serum Of Glaucoma Patients Supplemented With Macular Pigment Carotenoids., Joy Udensi, Ekaterina Loskutova, James Loughman, Hugh J. Byrne

Datasets

Carotenoids have been widely studied for their high dietary, antioxidant, and vision protection roles in the human body. Blood contains all major dietary carotenoids and hence presents as a suitable and efficient substrate for the estimation of dietary carotenoids in vivo. Following the 18-month supplementation of open angle glaucoma patients with macula pigment carotenoids (Lutein, Zeaxanthin and Meso-Zeaxanthin) in the European Nutrition in Glaucoma Management (ENIGMA) trial, Raman spectroscopic analysis of the pre-supplementation baseline and 18-month supplemented blood serum carotenoids from participants was carried out, to investigate the systemic impact of supplementation in the blood and explore a more direct …

Mechanistic Analysis Of Four-Way Dna Junctions And Cytokine-Binding Aptamers For Therapeutic Interventions, Roaa S. Mahmoud

Theses and Dissertations

DNA is inherently dynamic and topologically diverse and can fold into many different structures. Besides the canonical Watson-Crick structure, other higher-order structures such as G-quadruplexes (G4), i-motifs (iM), and four-way DNA junctions are possible. Although these high-order DNA structures are known to form transiently, they are important due to the crucial roles they play in many cellular processes including DNA replication, recombination, and repair. Among these DNA structures, 4-way junctions (also known as Holliday junctions, HJ) which are formed during the repair of double-strand DNA breaks (DSBs) and interact with proteins have garnered significant attention due to their central role …

Synthesis And Biophysical Analysis Of Modified Cell-Penetrating Peptides, Joel Mitchell

Theses and Dissertations (Comprehensive)

Cell-penetrating peptides (CPPs) are a family of peptides that have the ability to penetrate biological membranes. They were discovered in the late 1980s and have been the topic of many studies. Much of the interest in CPPs has been due to their ability to translocate biological membranes, and the possibility that they could offer a novel drug delivery method by conjugation to biologically active molecules. Linear CPPs can be modified to form cyclic structures. This change in structure has been observed to enhance the stability and penetrative ability of the CPPs which have been studied. The current thesis focuses on …

Reducing Food Scarcity: The Benefits Of Urban Farming, S.A. Claudell, Emilio Mejia

Journal of Nonprofit Innovation

Urban farming can enhance the lives of communities and help reduce food scarcity. This paper presents a conceptual prototype of an efficient urban farming community that can be scaled for a single apartment building or an entire community across all global geoeconomics regions, including densely populated cities and rural, developing towns and communities. When deployed in coordination with smart crop choices, local farm support, and efficient transportation then the result isn’t just sustainability, but also increasing fresh produce accessibility, optimizing nutritional value, eliminating the use of ‘forever chemicals’, reducing transportation costs, and fostering global environmental benefits.

Imagine Doris, who is …

The Mechanobiology Of Cell Plasticity, Yuan Hong

McKelvey School of Engineering Graduate Student Theses & Dissertations

The cell is a sophisticated machine, integrating chemical and physical inputs to decide upon the mechanobiological outputs that the body requires every second, in cardiomyocytes that make heartbeats, in fibroblasts that heal wounds, and in sarcomeres that contract muscles. Malfunction of mechanotransduction or mechanical inputs is implicated in diseases such as fibrosis, cancers, and cardiomyopathies, and a pressing quest is underway to unravel the intricacies of how mechanical force orchestrates the activation of cells. This dissertation explores these fundamental mechanisms of cell activation using integrated mathematical and engineered cell culture models. The work begins with the discovery that the directionality …

Design Of An Fgf-1-Fgf-2 Heterodimer Variant With Enhanced Stability And Cell Proliferation Activity, Nicholas Alan Pohlman

Chemistry & Biochemistry Undergraduate Honors Theses

The FGF-1 subfamily, composed of FGF-1 and FGF-2, assists in broad health-related processes such as cell proliferation and angiogenesis respectively.^1,2 The subfamily shows promising signs as a therapeutic, however, the inherent thermal instability leads to a low half-life in vivo.³ To assist in improving the stability, FGF-1 and FGF-2 were connected via a 12-residue glycine linker ultimately producing a heterodimer. This heterodimer was further examined to discover its novel properties. Inspiration for this project was drawn from previous research which performed five mutations on FGF-1 ultimately improving stability in the protein complex. In addition to these five …

Understanding The Kinetics Of Laser-Induced Nanowelding Of Nanoparticles And The Motility Of Bacteria When Faced With Obstacles, Ariel Rogers

Graduate Theses and Dissertations

This dissertation has two focus areas: nanoparticle nanowelding and bacteria motility in the presence of micrometer sized structures. There are two main projects for the nanoparticle nanowelding studies: “Real-time imaging of laser-induced nanowelding in solution” and “Two-color laser-induced nanostructure shape modulation.” For the real-time imaging project, I used a fluorescence microscope, a 405 nm laser, and various python packages to quantify the average size of nanowelded nanostructures as a function of time and found that the average nanostructure growth over time fit the parameters of A¯(t) ∝ c0(1−e−t/τ), where c0 represents the initial concentration of nanoparticles in the solution and …

Evaluating The Response Of Glycine Soja Accessions To Fungal Pathogen Macrophomina Phaseolina During Seedling Growth, Shirley Jacquet, Layla Rashad, Sonia Viera, Francisco Reta, Juan Reta

Biological Science Student Working Papers

Charcoal rot caused by the fungal pathogen Macrophomina phaseolina (Tassi) Goid is one of various devastating soybean (Glycine max (L.) Merr.) diseases, which can severely reduce crop yield. The investigation into the genetic potential for charcoal rot resistance of wild soybean (Glycine soja) accessions will enrich our understanding of the impact of soybean domestication on disease resistance; moreover, the identified charcoal rot-resistant lines can be used to improve soybean resistance to charcoal rot. The objective of this study was to evaluate the resistance of wild soybean accessions to M. phaseolina at the seedling stage and thereby select the disease-resistant lines. …

Langevin Dynamic Models For Smfret Dynamic Shift, David Frost, Keisha Cook Dr, Hugo Sanabria Dr

Annual Symposium on Biomathematics and Ecology Education and Research

No abstract provided.

Shedding Light On Cellular Glycolysis Pathway Kinetics: Combining Kinetic, Mechanistic Modelling Approaches With Label Free Microspectroscopic Imaging. (Cytomechspec), Nitin Patil

Articles

Glycolysis pathway kinetics in cells are known to be modulated for several disorders (cancers, neurodegenerative disorders, diabetes, etc.) and are currently been targeted as a biomarker for disease diagnostics and therapy. Although there are several approaches for monitoring the pathway kinetics, ranging from simple kinetic biochemical assays to sophisticated omics techniques, there remains a significant gap in the field, as there is a noticeable compromise between the extent of insights achievable from approaches which are destructive to the sample, and the real-time, kinetic analysis of a system.

Vibrational spectroscopy is a powerful, label-free, non-invasive tool capable of sub-cellular resolution, the …

Substrate Specificity In Abc Transporters Using The E. Coli Methionine Import System, John H. Guardado

Featured Student Work

ATP-binding cassette (ABC) transporters use the energy of ATP to move substrates across membranes against a concentration gradient. The role of ABC transporters is crucial in several essential cellular functions and mutations in ABC transporters in humans have been linked to several conditions, including cystic fibrosis, liver disease, and diabetes. Despite their central roles in homeostasis, the mechanism of ABC transporters remains poorly understood. Our research is focused on studying an ABC importer in E. coli, as a model system, to examine the mechanism of substrate specificity and transport. The bacterial methionine import system consists of a membrane-embedded transporter, MetNI, …

Using Hyperosmotic Shock To Study The Cell Wall Of Myxococcus Xanthus, Ian Sabol

Harrisburg University Research Symposium: Highlighting Research, Innovation, & Creativity

No abstract provided.