Biochemistry, Biophysics, and Structural Biology Commons^™

Soil Nutrient Sufficiency Versus Plant Nutrient Status In Compost-Amended Soils: Plant Tissue Analysis As A Diagnostic Tool, Chandralekha Joga Miss

Murray State Theses and Dissertations

This study evaluated whether Mehlich III soil nutrient sufficiency ratings reliably predict plant nutrient status and chlorophyll response across contrasting compost application histories. A greenhouse pot experiment was conducted with Chijimisai (Brassica rapa) planted in three treatment soils that had no compost (T1), moderate compost history (T2), and long-term hog manure compost application (T3). Plant performance was assessed through weekly shoot length and chlorophyll content (SPAD) measurements, leaf number at maturity, and leaf tissue nutrient analysis conducted at harvest. Soil test results indicated adequate to high nutrient levels across all three treatments. Leaf tissue analysis, however, revealed substantial …

Overview And Methods Of Molecular Paleontology: A Review, Shelby Touchstone

Williams Honors College, Honors Research Projects

Molecular paleontology—the study of ancient biomolecules preserved in fossils and sediments, including ancient DNA, lipids, and proteins—has motivated researchers since the 1950s, inspiring both scientific inquiry and broader cultural imagination. Think Jurassic Park. This honors thesis presents a comprehensive review of the history, current state, and methods of the field of molecular paleontology. Drawing on peer-reviewed literature and scholarly resources accessed through databases such as EBSCO and Bierce library, this review examines key techniques such as Next Generation Sequencing and amino acid racemization and will go over limitations and controversies in the field. It will also explore potential new …

The Synergy Between A Silver-Ruthenium Antimicrobial And Aminoglycosides Is Based On Severe Macromolecular Damage, Emmanuel Parkay Oladokun

Theses and Dissertations

The rise of multidrug-resistant (MDR) bacterial pathogens, including uropathogenic Escherichia coli (UPEC), highlights the urgent need for alternative treatment strategies to restore antibiotic efficacy. The silver-ruthenium antimicrobial AGXX exerts potent bactericidal effects through the production of reactive oxygen species (ROS); however, its potential synergy with antibiotics has not been thoroughly investigated. Here, we show that sublethal concentrations of AGXX strongly enhance aminoglycoside-mediated killing across a diverse panel of Gram-negative and Gram-positive MDR clinical isolates, including highly aminoglycoside-resistant strains. Combinational treatments significantly reduced the effective concentrations of gentamicin, tobramycin, kanamycin, and amikacin required to kill bacteria. Mechanistic analyses revealed that AGXX/aminoglycoside …

Interaction Of The Gram-Positive Human Pathogen Staphylococcus Aureus With Host Lipids, Sharanya Paul

Theses and Dissertations

Staphylococcus aureus is a prominent pathogen that is known to incorporate straight-chain unsaturated fatty acids (SCUFAs) into its lipids in addition to the normally biosynthesized branched-chain fatty acids (BCFAs) and straight-chain fatty acids (SCFAs). Furthermore, it has recently been shown that the incorporation of oleic acid into S. aureus lipids significantly enhanced the growth of the organism at low temperatures due to the greater fluidity imparted to the membrane. Together with others in the Wilkinson and Dahl laboratory, I have shown that low-temperature growth is enhanced by various SCUFAs, including the human antimicrobial fatty acids sapienic acid, linoleic acid, and …

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

Doctoral

Cellular metabolism and its intricate biochemical mechanisms which allow the conversion of nutrients into energy to sustain life are well understood, leading to numerous breakthroughs in science and technology, human health and wellbeing. From an industrial perspective the pathway kinetics are significant for monitoring cellular bioprocesses, screening desired metabolite phenotypes in drug discovery processes, etc.

An initial review of glycolysis pathway kinetics highlighted the lack of sophisticated approaches to monitor the metabolic pathway kinetics as a function of time in a non-destructive, non-invasive, label-free manner. Fluxomics, a metabolomics based approach providing high-throughput insights, can be considered a gold standard approach, …

Evaluating Novel Targeted Combination Therapies For Gastrointestinal Cancers, Joseph A. Goode

Graduate Studies Theses and Dissertations 2026

Gastrointestinal (GI) cancers remain among the leading causes of cancer-related mortality worldwide, with therapeutic resistance continuing to limit the effectiveness of current treatments. Three complementary studies were conducted to identify therapeutic vulnerabilities and evaluate novel combination strategies in pancreatic ductal adenocarcinoma (PDAC) and colorectal cancer (CRC).  First, dual inhibition of fibroblast growth factor receptor 4 (FGFR4) and phosphoinositide 3-kinase (PI3K)/mammalian target of rapamycin (mTOR) signaling was investigated in PDAC models. A combination of targeted drug treatments reduced viability, clonogenic survival, migration, and suppressed signaling pathways involved in translational control. This supported a functional interaction between FGFR4 and PI3K-mTOR co-activation in …

The Biosynthesis Of The Natural Product N-Nitroglycine, Gabriel Padilla

Graduate Studies Theses and Dissertations 2026

N-Nitroglycine (NNG) is a nitramine [R(R′)N–NO2; R′=H or alkyl] natural product (NP) produced by certain actinomycetes, such as Streptomyces noursei. At the beginning of this project, the biosynthesis of this NP was unknown. The goal was to determine how NNG and its nitramine moiety are enzymatically formed. This could lead to the discovery of novel nitramine NPs with diverse applications as well as alternative/green synthesis of nitramine explosives. This work begins by examining diverse biochemical N–N bond formation strategies. Nitrogen cycle enzymes, nitration of NPs, kutzneride biosynthesis, the aspartate/nitrosuccinate superfamily, hydrazinoacetic acid (HAA) biosynthesis, and streptozocin biosynthesis are among the …

Cell Type-Specific Fatty Acid Signalling And Its Sex Dependence, Emeline Masterson

Graduate Studies Theses and Dissertations 2026

Dietary fat is a highly palatable, energy-dense nutrient whose oral detection powerfully shapes ingestion patterns and metabolic outcomes. Despite clear behavioral and physiological evidence that fat can evoke distinct taste signals, the cellular and molecular mechanisms underlying its transduction remain poorly understood. A critical gap exists in our understanding of the cell-type-specific molecular pathways and how these signals are modulated by hormonal status. This dissertation delineates estrogen-dependent plasticity in FA transduction within the peripheral taste system, revealing coordinated, sex and cell-type-specific modulation of these pathways. To understand the missing mechanisms, FA-evoked responses were compared in Type II cells from wild-type …

Physicochemical Characterization Of Small Extracellular Vesicles: Effects Of Immobilization, Isolation, And Disease State, Bianca M. Mercado Velez

Dissertations, Master's Theses and Master's Reports

Cancer treatments and survival outcomes have improved significantly in the last couple of decades, with survival rates increasing in the U.S. Despite improvements in treatment outcomes, early detection and treatment are crucial for improving cancer prognosis and survival rates. The standard cancer diagnostic procedure of tissue biopsy is highly invasive, leading to the further spread of cancer in some cases. Alternatively, the extraction of biofluids from cancer patients, also called a liquid biopsy, is increasingly popular because it is less invasive and more representative of the tumor microenvironment, which contains cancer cells, tumor genetic material, and extracellular vesicles, including small …

Targeted And Screening Based Approaches To Analyze Drm Transcriptional Repressor Complex Activity In Caenorhabditis Elegans, Emily Washeleski

Dissertations, Master's Theses and Master's Reports

The molecular machinery that control the eukaryotic cell cycle, specifically the processes that mediate the switch between cellular division or quiescence, are essential for cellular and organismal viability. However, how the same machinery integrates with developmental or differentiation programs is less well understood. In Caenorhabditis elegans, the 8-subunit DRM complex (for Dp, Rb and MuvB), whose subunits belong to the Synthetic Mulitivulva (SynMuv) B class genes, is a central regulator of the cell cycle but also prevents inappropriate cell fate specification. The conserved mammalian DREAM complex (for Dp, Rb, E2F, And MuvB) is best known as a transcriptional repressor …

Deer Antler Tip Cell Culture Supernatant Restores Endothelial Barrier Function And Angiotensin Converting Enzyme 2/Endothelial Nitric Oxide Synthase Nitric Oxide Signaling Impaired By Porphyromonas Gingivalis Lipopolysaccharide, Ming-Shou Hsieh, Ya-Ting Yang, Chin-Sheng Huang, Ting-Yi Renn, Chuen-Kai Wang, Chia-Chen Hsu, Wei Jen Chang, Yu-Sheng Chang

Journal of Dental Sciences

Background/purpose:

Periodontal inflammation contributes to endothelial dysfunction, but effective biologically active strategies for vascular protection remain limited. This study investigated whether deer antler tip cell culture supernatant could rescue Porphyromonas gingivalis lipopolysaccharide (Pg-LPS) induced endothelial injury and restore endothelial homeostasis.

Materials and methods:

Velvet antler tissues from the tip, shaft, and burr regions were examined histologically and used for primary cell isolation. Human umbilical vein endothelial cells were exposed to Pg-LPS or indirectly co-cultured with LPS-stimulated THP-1-derived macrophages. Deer antler tip cell culture supernatant was subsequently applied to these endothelial inflammatory models, and its protective effects were …

Methylseleninic Acid Transformations In Nutrient Rich Water Containing Algae Exposed To Simulated Sunlight, Mikayla Cormier

Theses and Dissertations (Comprehensive)

Methylseleninic acid (MSA(IV)) is an organic form of selenium that has been suggested to be one of the most bioaccumulative forms of selenium in aquatic ecosystems. However, there have been no lab studies that confirm this, which is the reason this study was conducted. Once MSA(IV) and other bioavailable forms of selenium enter aquatic ecosystems, organisms such as algae take up these compounds which then bioaccumulate through the food chain. S. obliquus was exposed to 10 ppb MSA(IV) in 10% Bold’s basal medium (BBM) in a growth chamber to mimic environmental conditions over a 7-day period. Carbon traps and filters …

31p Solution Nmr Investigation Of Abasic Dna, Clarissa R. Krimmel

Graduate Theses/Dissertations

Base excision repair (BER) mechanisms fix single base lesions in DNA, such as T:G mismatches. During the base excision repair mechanism, an abasic site (AP site) is formed as an intermediate. AP sites are unstable and highly mutagenic; they can stop DNA replication. This research investigates how the conformational properties of abasic sites in DNA affect the binding recognition of enzymes involved in DNA repair mechanisms, including BER. Three different abasic sequences are being analyzed for this research project. A second project looks at the effects of a naturally occurring purine derivative, hypoxanthine, on the DNA backbone. These hypoxanthine lesions …

Comparing The Differences Of Hsp90Α And Hsp90Β In Native Protein Complex Incorporation, Daryna Serediuk

Honors Theses and Capstones

Epichaperomes are long-lasting, stable assemblies of chaperones, co-chaperones, and associated factors that facilitate cell survival in maladaptive cellular states. Their inhibition has emerged as an attractive therapeutic strategy for the treatment of cancer and neurodegenerative diseases (Rodina et al., 2016). Epichaperomes are hallmarks of robust proliferation in cancer cell populations across many cancer types and are abundantly present in several stem cell varieties, including induced pluripotent stem cells, human embryonic kidney cells, and cancer stem cells (Kishinevsky et al., 2018).

The core protein of the eukaryotic heat shock protein machinery, Heat Shock Protein 90 (Hsp90), is a central chaperone that …

How Semiflightless Birds Adapt: A Survey From Barú, Costa Rica, Eli P. Laloudakis

Scripps Senior Theses

When we think of birds, we think of flight. Because of this, scientific research often focuses on how birds evolved flight and how their wings function during flight. However, not all birds can fly or fly well, as wings wax and wane on developmental, seasonal, and evolutionary time scales (Dial and Heers 2021). Consequently, rudimentary wings can be found in developing birds, secondarily flightless or semiflightless birds, birds that undergo simultaneous molts, and extinct theropods with “protowings” (structures that preceded fully functional wings). Secondarily flightless and semiflightless birds often evolve where there is no/low predation, abundant year-round food supply, and …

Seeing Through The Fuzz: Understanding Conformational Diversity In The Fuzzy Coat Of Amyloids Across Fibril Polymorphs Using Solid-State Nmr, Carah K. Allen

Scripps Senior Theses

The aggregation of α-synuclein (α-syn) into amyloid fibrils is a central pathological hallmark of Parkinson’s disease and other related synucleinopathies. Although monomeric α-syn is intrinsically disordered, the protein assembles into multiple fibril polymorphs that differ in their β-sheet core structures. Surrounding each polymorph is the “fuzzy coat,” which is a highly dynamic, intrinsically disordered region (IDR) that is not resolved by high-resolution structural techniques, such as Cryo-EM, but is thought to influence fibril interactions, propagation, and toxicity. Understanding whether different polymorphs maintain distinct fuzzy-coat conformational ensembles is therefore essential for connecting amyloid structure to biological function. To address this question, …

Entropic Forces Near Fluctuating Surfaces, Rubayet Hassan

Dissertations

Nanoscale structures are inherently dynamic due to persistent thermal fluctuations. Even in solid materials, these random deformations, driven by ambient thermal energy, can become significant when their characteristic scale approaches that of the structure itself and strongly influence their overall mechanical behavior. Examples of such structures include crystalline membranes, appearing in diverse forms such as nanotubes, nanoribbons, and kirigami/origami structures. Similarly, biological nanostructures, including lipid membranes, microtubules, actin filaments, and DNA, exhibit extreme flexibility and responsiveness due to their low bending rigidity. Numerous physiological processes are intrinsically linked to these thermal fluctuations, including exocytosis and endocytosis, membrane fusion, pore formation, …

Understanding The Fidelity And Specificity Of Dna Polymerase I, Bill R. Miller Iii, Andrew V. Yeager, Jake A. Collins, Alexis Blake, Elise Tate, Carol A. Parish, Eugene Y. Wu

Chemistry Faculty Publications

High-fidelity DNA polymerases employ complex mechanisms to catalyze template-dependent DNA synthesis while quickly discarding mismatches. Atomic-level structural details about short-lived states during nucleotide discrimination are necessary to gain insight into the kinetic checkpoints that contribute to fidelity. We performed microsecond molecular dynamics simulations of DNA polymerase I, large fragment, from Bacillus stearothermophilus (Bacillus fragment, or BF) in complex with a template guanine and a mismatched thymidine triphosphate to observe the early events in the process of selection against a mismatch. Although the nucleobases formed a wobble base pair early, the mismatched pair was blocked from fully entering the active site …

Potency Dependent Angiogenic Effect Of Bellis Perennis On In Ovo Chick Chorioallantoic Membrane Assay, Jayanthdevan V, Winston Vargheese V, Anish Fathima K, Lohita S

Indian Journal of Research in Homoeopathy

Background: Hormesis is the biological response of an organism for a particular dosage of a substance. The lower dose stimulates and higher dose inhibits. J Compton Burnett, an eminent homeopath, prescribed Bellis perennis for breast and uterine tumours, which suggests it could be due to the antiangiogenic property or angiogenic inhibiting property and clinically also it is used for healing of fractured bone and wound healing which may be due to angiogenic promoting property. This experiment deals with the dose dependent effect of Bellis perennis on In Ovo Chick Chorioallantoic Membrane Assay. Objective: To evaluate the Hormesis effect of Bellis …

Microtubule Self-Organization With Active And Passive Crosslinkers, Prashali Chauhan

Dissertations - ALL

Humans have always been trying to unravel principles that guide how things around us function, all the way from galactic ovements to basic building blocks of matter. The physical and chemical properties of ‘biological’ systems govern processes all the way from molecular interactions of proteins to the form and function of individual living organisms. In this work, I focus on the proteins which help give shape and structure to the smallest building block of life, the cell and associated mechanisms of building fundamental cellular architectures, like the mitotic spindle. Mitosis takes place by microtubules aligning themselves in anti-parallel fashion with …