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Full-Text Articles in Other Biochemistry, Biophysics, and Structural Biology

Fbg Αc 389 – 402 Modulates Factor Xiii Crosslinking In The Fibrinogen Αc Region., Francis Dean Orlina Ablan Aug 2023

Fbg Αc 389 – 402 Modulates Factor Xiii Crosslinking In The Fibrinogen Αc Region., Francis Dean Orlina Ablan

Electronic Theses and Dissertations

Fibrinogen (Fbg) is a coagulation protein critical for clot formation. Coagulation Factor XIII (FXIII) is a calcium-dependent transglutaminase that crosslinks reactive glutamines (Q) and lysines (K) between fibrin and other anti-fibrinolytic proteins. In the presence of Ca2+, FXIII could be activated non-proteolytically (FXIII-A°), or proteolytically by thrombin (FXIII-A*). Significant increases in clot stability and red blood cell retention are linked to FXIII activity in the fibrinogen αC region (Fbg Aα 221 – 610). This region contains several FXIII-reactive glutamines and lysines, as well as a binding site for FXIII-A* (Fbg αC 389 – 402) that includes a key …


Quantum Computations And Molecular Dynamics Simulations: From The Fundamentals Of Antimicrobial Resistance To Neurological Diseases, Angel Tamez Dec 2022

Quantum Computations And Molecular Dynamics Simulations: From The Fundamentals Of Antimicrobial Resistance To Neurological Diseases, Angel Tamez

Electronic Theses and Dissertations

Biophysical phenomena are modeled using a combination of quantum and classical methods to interpret and supplement three distinct and diverse problems in this dissertation. In the first project, decarboxylation reactions are ubiquitous across chemical and biological disciplines, yet the origin of non-catalytic solvent effects remains elusive. Specific solvent structure and energetics have not been well described for the monoanion of malonate, nor corrected from the gas-phase charge-assisted intramolecular hydrogen bond model known as “pseudochair”. In the aqueous phase, a low-lying energy conformer known as the “orthogonal conformation” is computed to be preferred by a three-water cluster of hydrogen bonding over …


Applications Of Nuclear Magnetic Resonance Spectroscopy: From Drug Discovery To Protein Structure And Dynamics., Mark Vincent C. Dela Cerna Aug 2022

Applications Of Nuclear Magnetic Resonance Spectroscopy: From Drug Discovery To Protein Structure And Dynamics., Mark Vincent C. Dela Cerna

Electronic Theses and Dissertations

The versatility of nuclear magnetic resonance (NMR) spectroscopy is apparent when presented with diverse applications to which it can contribute. Here, NMR is used i) as a screening/ validation tool for a drug discovery program targeting the Phosphatase of Regenerating Liver 3 (PRL3), ii) to characterize the conformational heterogeneity of p53 regulator, Murine Double Minute X (MDMX), and iii) to characterize the solution dynamics of guanosine monophosphate kinase (GMPK). Mounting evidence suggesting roles for PRL3 in oncogenesis and metastasis has catapulted it into prominence as a cancer drug target. Yet, despite significant efforts, there are no PRL3 small molecule inhibitors …


Molecular Dynamics Simulations Provide Insight Into Stability Of Hyperthermophilic Endoglucanases, Logan E. Sheffield Jun 2021

Molecular Dynamics Simulations Provide Insight Into Stability Of Hyperthermophilic Endoglucanases, Logan E. Sheffield

Electronic Theses and Dissertations

Endoglucanases play a key role in the industrial production of bioethanol, but the most efficient method requires the utilization of high temperatures and is currently limited by the thermostability of endoglucanases. For this reason, it would be beneficial to discover more high-efficiency, thermostable enzymes to utilize in the hydrolytic process. In this study molecular dynamics simulations were performed on structurally similar endoglucanases with varying levels of thermostability to gain insight on what factors contribute to thermostability in endoglucanases. RMSD, RMSF, PCA, hydrogen bonding and salt bridges were analyzed. Finally, protein energy networks were constructed from nonbonded interaction potentials and analysis …


Structural Characterization And Selective Drug Targeting Of Higher-Order Dna G-Quadruplex Systems., Robert Chandos Monsen Dec 2020

Structural Characterization And Selective Drug Targeting Of Higher-Order Dna G-Quadruplex Systems., Robert Chandos Monsen

Electronic Theses and Dissertations

There is now substantial evidence that guanine-rich regions of DNA form non-B DNA structures known as G-quadruplexes in cells. G-quadruplexes (G4s) are tetraplex DNA structures that form amid four runs of guanines which are stabilized via Hoogsteen hydrogen bonding to form stacked tetrads. DNA G4s have roles in key genomic functions such as regulating gene expression, replication, and telomere homeostasis. Because of their apparent role in disease, G4s are now viewed as important molecular targets for anticancer therapeutics. To date, the structures of many important G4 systems have been solved by NMR or X-ray crystallographic techniques. Small molecules developed to …


Dynamic Regulation Of G-Protein Signaling, William C. Simke Aug 2019

Dynamic Regulation Of G-Protein Signaling, William C. Simke

Electronic Theses and Dissertations

G protein-coupled receptors (GPCRs) are involved in numerous signaling processes ranging from neuronal growth to immune cells tracking invaders. GPCR signaling plays a role in many human diseases and thus GPCRs are important drug targets. Yeast respond to mating pheromone using a GPCR signaling system homologous to those used in humans to polarize their cytoskeleton toward the pheromone source. This is accomplished by initializing a MAPK signaling cascade to arrest the cells in mitosis and upregulate expression of chemotropic proteins. Pathway desensitization is accomplished by the Regulator of G-protein Signaling (RGS). RGS abrogates signaling by binding to the active GPCR, …


Targeted-Ion Mass Spectrometry For The Identification Of Forensically Relevant Biological Fluids And Samples From Sexual Assault Evidence, Heather Erin Mckiernan Jan 2019

Targeted-Ion Mass Spectrometry For The Identification Of Forensically Relevant Biological Fluids And Samples From Sexual Assault Evidence, Heather Erin Mckiernan

Electronic Theses and Dissertations

Forensic practitioners have long sought efficient and reliable means for identifying those samples that are best suited for successful genetic profiling. Traditional serological screening methodologies rely upon enzyme activity and antibody-based serological tests. These tests can be consumptive, laborious and costly while reliance on antibody-based serological testing can be prone to error. Positive results resulting from non-target biological fluids, the potential for cross- reactivity and non-specific binding events yield merely presumptive results. This has led forensic biologists to omit serological testing, at least in the case of sexual assault kit samples, in favor of Y-Screen assays. While these Y-Screen approaches …


Biophysical Exploration Of Conformational Environments In Zymogen Prothrombin And Blood Coagulant Thrombin., Ramya Billur May 2018

Biophysical Exploration Of Conformational Environments In Zymogen Prothrombin And Blood Coagulant Thrombin., Ramya Billur

Electronic Theses and Dissertations

The serine protease thrombin plays important roles in coagulation, anticoagulation, and platelet activation. Thrombin is initially expressed as the inactive zymogen prothrombin (ProT). The final cleaved and activated form of thrombin has mature anion binding exosites (ABEs) and several regulatory loops. Engagement with these exosites helps define the fate of thrombin as a procoagulant or an anticoagulant. Researchers previously reported that zymogen ProT may already bind exosite ligands. Little is known about conformational changes associated with ProT maturation, resultant ligand binding affinities, individual ligand-protein contacts, and long-range communication between thrombin exosites. Protease Activated Receptors (PARs) play critical roles in controlling …


Improving The Detection Limit Of Tau Aggregates For Use With Biological Samples, Emily Rickman Hager Jan 2018

Improving The Detection Limit Of Tau Aggregates For Use With Biological Samples, Emily Rickman Hager

Electronic Theses and Dissertations

The protein Tau is found in neurofibrillary tangles in Alzheimer's disease and over 20 other neurodegenerative diseases. An assay has been developed to detect minute amounts of fibrils from human brain tissue. This assay subjects brain tissue extract and recombinant Tau to several rounds of sonication and incubation. Incubation allows recombinant Tau to add itself to the ends of the existing fibrils in brain tissue extract. Sonication breaks the existing fibrils in the brain tissue extract offering more ends for Tau to add onto. Cycles of sonication and incubation have been shown to allow for amplification of Tau fibrils from …


Modeling The Binding Of Neurotransmitter Transporter Inhibitors With Molecular Dynamics And Free Energy Calculations, Bernandie Jean Jan 2017

Modeling The Binding Of Neurotransmitter Transporter Inhibitors With Molecular Dynamics And Free Energy Calculations, Bernandie Jean

Electronic Theses and Dissertations

The monoamine transporter (MAT) proteins responsible for the reuptake of the neurotransmitter substrates, dopamine, serotonin, and norepinephrine, are drug targets for the treatment of psychiatric disorders including depression, anxiety, and attention deficit hyperactivity disorder. Small molecules that inhibit these proteins can serve as useful therapeutic agents. However, some dopamine transporter (DAT) inhibitors, such as cocaine and methamphetamine, are highly addictive and abusable. Efforts have been made to develop small molecules that will inhibit the transporters and elucidate specific binding site interactions. This work provides knowledge of molecular interactions associated with MAT inhibitors by offering an atomistic perspective that can guide …


Modulation Of Cell Death Signaling And Cell Proliferation By The Interaction Of Homoserine Lactones And Paraoxonase 2., Aaron Mackallan Neely May 2016

Modulation Of Cell Death Signaling And Cell Proliferation By The Interaction Of Homoserine Lactones And Paraoxonase 2., Aaron Mackallan Neely

Electronic Theses and Dissertations

Pseudomonas aeruginosa produces N-(3-oxododecanoyl)-homoserine lactone (C12) as a quorum-sensing molecule that functions to facilitate bacteria-bacteria communication. C12 has also been reported to affect many aspects of human host cell physiology, including evoking cell death in various types of cells. However, the signaling pathway(s) leading to C12-triggerred cell death remains unclear. To clarify cell death signaling induced by C12, we examined mouse embryonic fibroblasts (MEFs) deficient in one or more caspases. Our data indicate that, unlike most apoptotic inducers, C12 evokes a novel form of apoptosis in cells, probably through the direct induction of mitochondrial membrane permeabilization. Previous studies indicate that …


Regulation Of Actin Dynamics During Drosophila Germband Extension, Ashley M. Motlong Jan 2013

Regulation Of Actin Dynamics During Drosophila Germband Extension, Ashley M. Motlong

Electronic Theses and Dissertations

Convergent extension is a process that occurs in the development of a wide variety of organisms, including gastrulation in the Drosophila embryo to begin to lay out the adult body plan. In fly embryos, this is known as germband extension and is mainly driven by cell intercalation or neighbor exchange by planar polarized cell-cell interface contraction to shorten the tissue along the dorsal-ventral axis. In this thesis, I show that interface contraction consists of phases of fast interface shortening and intervals of stable interface size. My data also suggests that regulation of F-actin aggregates at these shrinking interfaces is important …


A Hydrodynamic Method For Measuring Aqueous Nanoparticle Surface Interactions, Kellen John Sorauf Jan 2012

A Hydrodynamic Method For Measuring Aqueous Nanoparticle Surface Interactions, Kellen John Sorauf

Electronic Theses and Dissertations

The objectives of this research dissertation were to develop and present novel analytical methods for the quantification of surface binding interactions between aqueous nanoparticles and water-soluble organic solutes. Quantification of nanoparticle surface interactions are presented in this work as association constants where the solutes have interacted with the surface of the nanoparticles. By understanding these nanoparticle-solute interactions, in part through association constants, the scientific community will better understand how organic drugs and nanomaterials interact in the environment, as well as to understand their eventual environmental fate. The biological community, pharmaceutical, and consumer product industries also have vested interests in nanoparticle-drug …