Biochemistry, Biophysics, and Structural Biology Commons^™

Investigating The Ability Of Presequences To Influence Mitochondrial Protein Import, Youmian Yan

WUSM Theses and Dissertations – All Programs

Mitochondria are essential organelles housing over 1000 proteins, 99% of which are nuclear-encoded and synthesized in the cytosol. Most mitochondrial proteins are targeted by a positively charged sequence called the presequence, which lacks a common sequence motif and is poorly conserved across evolution. Accumulating evidence suggests that presequences encode meaningful information that influences mitochondrial protein uptake. For instance, multiple stress response models propose that stress sensing proteins contain “weak” presequences which allows them to monitor mitochondrial health. However, there is a lack of systematic examination about how presequences influence import kinetics and what constitutes presequence strength. These gaps in knowledge …

Waste Streams From Next Generation Molten Salt Reactors: The Challenge Of Creating An Insoluble Ceramic For Chloride Salt Waste, Alevtina A. Maksimova, Jake W. Amoroso, Matthew Page, Gregory Morrison, Hans Conrad Zur Loye

Faculty Publications

Molten salt reactors (MSRs) design development is of interest to many research groups and companies. Waste management for MSRs is one of the most important issues that needs to be resolved due to its impact on environmental safety, primarily via the dissolution of radionuclides in water. Furthermore, the waste treatment strategy will have a significant influence on the operating cost of MSRs, which is why a reliable process for the immobilization, transportation, storage and disposal of MSR waste must be addressed. This work presents a new approach for the immobilization of chloride salts from molten salt reactors in stable oxyhalide …

Characterization Of Mettl3/14-Mediated M6a Modification In Human Transcriptome Using Nanopore Direct Rna Sequencing, Emily Kurtyan, Andrew J. Stein, Kelly J. Abdalla, Zhangerjiao Yuan, Miten Jain, Fadia Ibrahim

Department of Biochemistry and Molecular Biology Faculty Papers

Post-transcriptional RNA modifications modulate diverse aspects of RNA metabolism. N6-methyladenosine (m6A), one of the most abundant internal RNA modifications, is deposited by the core methyltransferase complex, METTL3 and METTL14. Oxford Nanopore Technologies (ONT) platform permits direct, single RNA molecule sequencing while preserving native modifications. However, without rigorous benchmarking, the accuracy and reproducibility of modification detection remain uncertain. Here, we leveraged ONT to comprehensively profile bona fide m6A modifications in cellular RNAs at single-nucleotide resolution by integrating two direct RNA sequencing chemistries (RNA002 and RNA004) with the m6Anet and Dorado modification-detection models. We independently depleted METTL3 and METTL14 in human cells …

Sec-Saxs And Sans Analyses Of The Talin•Vinculin Complex, Gilbert Reyes

Dissertations, Theses, and Capstone Projects

Focal adhesions (FA) are integrin-based cell-matrix adhesion sites composed of adaptor proteins that facilitate the generation of traction forces important for biological functions such as cell migration, embryo development, wound healing, tissue organization and stability, and immune responses. Mature FA are observed when both autoinhibited multi-domain scaffolding protein talin and membrane-cytoskeletal protein vinculin are activated and interact thus promoting the assembly and function of FA. While research has resolved truncated sections of autoinhibited talin and recruitment of vinculin due to mechanotransduction that exposes cryptic vinculin binding sites (VBS), little is known about the global modifications of full length talin in …

Evaluation Of Mdm2 Mrna Expression According To Clinicopathological Characteristics In Oral Squamous Cell Carcinoma (Oscc) Patients, Tirta Wardana

Chulalongkorn Medical Journal

Background: The murine double minute 2 (MDM2) gene encodes an E3 ubiquitin ligase that targets p53 for degradation, thereby influencing the pathogenesis of oral squamous cell carcinoma (OSCC).

Objective. The present study investigates MDM2 mRNA expression and its association with clinical and pathological characteristics in OSCC patients.

Methods: We conducted an observational-analytical study using a cross-sectional design. The study involved 39 OSCC patients. RNA extraction, cDNA synthesis, and quantitative PCR (qPCR) were performed. We quantified relative MDM2 mRNA expression using the Livak method (2-ΔΔCT) and GenEX MultiD software version 6.0. Statistical significance was assessed using independent t-tests.

Results: Although no …

Development Of Ultrafast Protein Digestion And Standards Free Quantitation Methods For Mass Spectrometric Analysis, Praneeth Ivan Joel Fnu

Dissertations

A wide variety of biologically important molecules, such as enzymes, antibodies, hormones, transporters and receptors are proteins by composition and they play key roles in biological functions such as cellular regulation, communication, metabolism and physiological function. Protein dysfunctions and abnormalities are associated with numerous diseases, making proteins critical targets for understanding disease mechanisms and developing therapeutic interventions. Protein-based therapeutics such as monoclonal antibodies, hormones and vaccines gained popularity due to their high specificity, efficacy, and ability to treat complex diseases that are often difficult to address with small-molecule drugs.

Given the important role of proteins in a variety of biological …

Modeling Kinetics Of 5-Aminolevulinic Acid-Induced Protoporphyrin Ix Accumulation For Optimal Photodynamic Therapy, Priscilla Melebor

Graduate Masters Theses

Photodynamic therapy (PDT) is a minimally invasive treatment that uses light-activated photosensitizers to selectively destroy diseased tissue through the generation of reactive oxygen species. However, conventional in vitro models often fail to accurately reproduce the pharmacokinetics of photosensitizer accumulation and clearance observed in vivo. This study investigated protoporphyrin IX (PpIX) accumulation following 5-aminolevulinic acid (ALA) exposure under physiologically relevant conditions using two-dimensional (2D) monolayers and three-dimensional (3D) spheroids. By comparing continuous ALA exposure with transient exposure followed by ALA washout, this work provides a more biologically relevant framework for studying PpIX kinetics and optimizing photodynamic therapy.

Synthesis, Utilization And Biological Evaluation Of Β-Hairpin Peptides As Inhibitors Of Immune Checkpoints, Sarah Naylon

Electronic Theses and Dissertations

Peptide therapeutics have emerged as promising alternatives to monoclonal antibodies because of their smaller size, improved tissue penetration, and synthetic versatility. Yet their broader application is often limited by poor structural stability, rapid clearance, and reduced target residence times. This dissertation describes the design, synthesis, structural characterization, and biological evaluation of β-hairpin peptides as inhibitors of immune checkpoints and as peptide vaccine scaffolds while developing strategies to overcome these limitations. At first a series of antibody-derived β-hairpin peptides (mimics of complementary determining region heavy-chain 3: CDR-H3s) as covalent inhibitors of the PD-1/PD-L1 immune checkpoint were investigated. Electrophilic warheads were incorporated …

Instruction Guide, Mark C. Hall

Analytical Biochemistry: A Practical Handbook for Undergraduates

The instruction guide provides useful information for setting up and running the lab activities each week and assessing student preparation, performance, and comprehension.

Enzymatic Synthesis Of Salicylate In Yersina Pestis Proceeds Via Intramolecular Hydroxyl Group Transfer., Clarke Miller

Georgia Journal of Science

The salicylate synthase (YbtS) of Yersinia pestis catalyzes the initial step in the biosynthesis of yersiniabactin, an iron-scavenging siderophore and critical virulence factor. While YbtS is proposed to share a  reaction mechanism with other anthranilate synthase homologs, the exact catalytic pathway has remained unresolved.  In this work, stable isotope (¹⁸O) labeling and mass spectrometry are utilized to clarify the catalytic mechanism of YbtS.  The results of the following set of experiments demonstrate that the salicylate hydroxyl group does not originate from solvent water, directly challenging previously proposed models. Instead, the lack of solvent-labeled oxygen incorporation and the absence …

A Comprehensive In-Silico Pipeline For The Discovery Of Non-Toxic, Stable Antimicrobial Peptides From Databases For Targeting Multi-Drug Resistant K. Pneumoniae, Pranab D. Sharma, Abdullah A. Noman, Al Hafiz

Faculty Articles

The rapid emergence of multidrug-resistant Klebsiella pneumoniae has significantly reduced the effectiveness of conventional antibiotics, highlighting the need for alternative therapeutic strategies. This study employed a comprehensive in silico pipeline to identify antimicrobial peptides (AMPs) targeting the essential DNA replication initiator protein DnaA. A total of 28,361 peptide sequences were collected from publicly available AMP databases and sequentially filtered based on peptide length, net charge, GRAVY score, instability index, antimicrobial activity, toxicity, hemolytic potential, aggregation propensity, sequence similarity and favorable amphipathic properties. Four peptides satisfied all selection criteria and were subjected to structural prediction, membrane-binding analysis, protein–DNA docking, protein–peptide docking, …

Towards The Synthesis Of Dragonamide E And Analogs Thereof, Dante Glover

Chemistry Theses

Leishmaniasis is a disease caused by a parasite spread through the female sand fly. It is categorized as a Neglected Tropical Disease and can cause very severe symptoms, even death, if left untreated. Symptoms include skin lesions that can cause permanent scarring, and mucosal membrane infections that can cause facial deformities. More aggressive forms of leishmaniasis can lead to infections of internal organs like the liver and/or spleen and can lead to death. Drug resistance of these parasites has rendered treatment limited and the side effects of which can be harmful as well.

Scientists looking towards new treatments for tropical …

Crystal Structure Of New Polar Rare Earth Borates Na2.62Ln2.12(Bo3)3 (Ln = Pr, Nd, Sm) Containing Isolated Bo3 Groups, Alevtina A. Maksimova, Mark D. Smith, Hans Conrad Zur Loye

Faculty Publications

Three new rare earth borates, Na2.62Ln2.12(BO3)3 (Ln = Pr, Nd, Sm), were synthesized via a high-temperature solution reaction using a BaCO3–H3BO3–NaF flux and structurally characterized by single-crystal X-ray diffraction analysis. The compounds crystallize in the orthorhombic space group Amm2 with lattice parameters a = 5.0985(10) Å, b = 11.180(2) Å, c = 7.1483(14) Å, and a unit cell volume of 407.48(14) ų (Z = 2) for Na2.62Pr2.12(BO3)3, a = 5.0983(10) Å, b = 11.181(2) Å, c = 7.1491(14) Å, and a unit cell volume of 407.51(14) ų (Z = 2) for Na2.62Nd2.12(BO3)3, and a = 5.08630(10) Å, b …

Single Crystal Growth Of The Orthoborate Nabalu(Bo3)2 And Optical Investigation Of Eu3+ And Tb3+ Doped Nabalu(Bo3)2, Alevtina A. Maksimova, Mark D. Smith, Lakshani W. Masachchi, Hans Conrad Zur Loye

Faculty Publications

Sodium barium lutetium borate NaBaLu(BO₃)₂ crystals were synthesized using a high-temperature solution method. The crystal structure of this layered orthoborate is described and corresponds to that of an extensive orthoborates family, NaBaR(BO₃)₂ (R = Sc, Y, Yb, Tb – Lu). NaBaLu(BO₃)₂ was doped by Eu³⁺ and Tb³⁺ to explore its performance as a host material and to investigate the luminescent properties of the Eu³⁺ and Tb³⁺ doped materials. The emission spectra of the NaBaLu(BO₃)₂:Ln (Ln = Eu, Tb) crystals are presented. The most …

Polyphenol Diet And Exercise As Neuroprotection From Effects Of Alzheimer's Disease, Michelle Morgan

Loma Linda University Electronic Theses, Dissertations & Projects

Healthy non-pharmacological lifestyle factors, such as regular physical exercise and a dietary supplementation, have been shown to significantly improve cognitive outcomes over time compared to a more sedentary lifestyle and poor diet. Furthermore, exercise may serve as a potential protective factor in attenuating the effects associated with cognitive decline that are characteristic of neurodegenerative disorders, such as Alzheimer's disease (AD). Further, evidence indicates that certain diet interventions can also attenuate the effects of neurodegeneration and positively impact longevity. Supplementation of polyphenols, such as ellagic acid (EA), which are abundant in pomegranate juice, may help provide neuroprotective benefits and elicit a …

A Genetic Analysis Of The Rare Endemic Astragalus Ripleyi Barneby, Juan Antonio Jaramillo-Chico

Master's Theses

Astragalus ripleyi Barneby is a rare endemic species found in the San Luis Valley of the southern portions of the Rocky Mountains in Colorado and New Mexico. Though not federally listed as endangered, the species is on the Bureau of Land Management’s Sensitive Species List, warranting protection and continued management. This study aims to provide information about the genetic health of the species to inform conservation efforts and provide updated management recommendations. A genetic health analysis was conducted investigating the levels of diversity present in the species, how genetic diversity is structured across the known range of the species and …

From Geometry To Recognition: A Quantitative Framework For Tcr-Pmhc Structural Analysis In The Age Of Predicted Structures, Kun Hee Kim

Dissertations and Theses (Open Access)

Recognition of antigen by a T cell begins with a single physical event, the engagement of the T cell receptor (TCR) with a peptide-major histocompatibility complex (pMHC), and this interaction is encoded in the geometry with which the receptor docks onto the composite pMHC surface. Whether that docking geometry is biologically organized, and whether the structures now produced at scale by prediction preserve recognition or only reproduce that organization, are the two questions this thesis addresses. Two gaps stand in the way. The first is a gap of measurement, because docking geometry has never been made quantitatively comparable across many …

The Rpm-1/Phr Signaling Hub Modulates Tau-Induced Neurodegeneration Through Regulation Of Microtubule Stability And Mapk Pathways In C. Elegans, Xinxing Ding

Theses and Dissertations

Neurodegenerative diseases, including Alzheimer's disease and frontotemporal dementia, are characterized by the accumulation of pathological tau proteins and progressive neuronal loss. Although research regarding tau-mediated toxicity is extensive, the specific pathology that determine whether neurons maintain homeostasis or succumb to collapse under tau-induced stress remain incompletely elucidated. A central, yet still insufficiently understood, feature of these diseases is the disruption of the microtubule (MT) cytoskeleton . The PHR protein family is evolutionarily highly conserved; within this family, RPM-1 in C. elegans functions as an intracellular signaling hub that regulates axon development, synapse formation, axon termination, and various microtubule-associated processes. This …

Bridging The Gap In Science Research: Preparing Students For College- Level Research In The Sciences, Victoria Helwig, Yaoguang Li

UConn Library Presentations

Many first-year students enter college unprepared to fully engage with scientific literature and academic library resources. Drawing on experiences from academic librarians working with STEM students, this session explores common gaps in science research skills, including navigating databases, identifying scholarly sources, and understanding the structure of scientific literature. Participants will be introduced to practical strategies and classroom-ready activities to better prepare students for college-level research. Discussion questions: What science research skills do students struggle with most when entering college? How can high school instruction better support these skills? Where can librarians and educators collaborate to support student success?

Analysis Of The Atypical Temperature Dependence And Conformational Changes During Turnover Of A Lactobacillus Chlorogenic Acid Esterase, Nathaniel Carl, Yianni Tsigaris, Dan Ji, Nora K. Anpree, Kellie K. Omori, Cedric P. Owens

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Many bacterial chlorogenic acid esterases (ChlEs) exhibit atypical temperature behavior, featuring activities that barely change with temperature and activity maxima that fall below the thermal denaturation point. This work focuses on a ChlE from Lactobacillus helveticus (Lh–ChlE), which has a flat temperature dependence. First, it was determined that conformational changes during Lh–ChlE turnover are not rate-limiting and that the overall rate depends on the chemical step at all temperatures. Next, Lh–ChlE’s temperature dependence was investigated using a conformational equilibrium model that assumes the existence of a temperature-dependent equilibrium between an active and an inactive conformation and an activation heat capacity …