Other Biochemistry, Biophysics, and Structural Biology Commons^™

From Sequence To Allostery: How Amino Acid Differences Rewire Coupled Conformational Heterogeneity In The Ptp Enzyme Family, Shivani Sharma

Dissertations, Theses, and Capstone Projects

Protein Tyrosine Phosphatases (PTPs) are critical regulators of cellular signaling, and their activity is often modulated through allosteric mechanisms. Allostery is defined as a chemical or conformational change in one site of the protein due to a binding event at another site. Although several studies have investigated aspects of allostery in PTPs, the mechanistic foundations underlying allosteric regulation remain poorly understood. Despite a highly conserved catalytic domain across PTPs, regions with low or no conservation suggest potential "rewiring" of allosteric networks. This raises key questions about the universality versus individuality of allosteric mechanisms across the PTP family.

In this work, …

Advanced Interactions Of Directed Energy With Retinal Pigment Epithelial Cells And Their Photochemical And Photothermal Responses, Jin B. Ha

Theses & Dissertations

Excess optical radiation can injure the retina through either rapid heat deposition (photothermal damage) or cumulative photo‑oxidative stress (photochemical damage), yet current laser‑safety limits treat these mechanisms as independent. To test that assumption, this dissertation integrated systematic wavelength, duration and temperature‑controlled laser exposures with live/dead fluorescence imaging in a melanin‑loaded hTERT‑RPE1 monolayer model. First, concurrent 447 nm (blue) and 2 µm (infra‑red) beams delivered for 200 s demonstrated a strong thermal–photochemical synergy: each beam alone was sub‑threshold (≤25 % lethality) but together produced 100 % RPE death without exceeding 50 °C, proving that modest heating markedly lowers the photon dose …

A Cancer Education Needs Assessment: Informing Middle-Aged Female Patients About The Relationships Between Obesity And Women’S Health Concerns In The Reproductive System, Breast, And Endometrial Health, Batul Mirza

MUSC Theses and Dissertations

Obesity significantly impacts women’s health, particularly among middle-aged women, by increasing the risk of hormone-sensitive cancers such as breast, endometrial, and reproductive system cancers. This study examines the educational needs of this demographic group regarding obesity-related cancer risks and explores effective intervention strategies. Obesity-induced mechanisms – hormonal imbalances, chronic inflammation, and insulin resistance – drive cancer susceptibility, emphasizing the need for targeted health education. The study employs a qualitative design, which includes interviews with subject matter experts (SMEs) and surveys of middle-aged women. The goal is to assess awareness, perceived barriers, and preferred learning methods. Findings suggest that with many …

Foldit Education Mode, Brett Schulz

Electronic Theses and Dissertations

Foldit education mode is a puzzle campaign within the protein folding video game Foldit. Education mode, initially designed as a classroom supplement for undergraduate biochemistry courses, has been expanded to provide a more comprehensive learning tool to players without a background in biochemistry. The edited and added levels teach players about protein biochemistry through playing puzzles designed to convey information and gameplay mechanics. The new Foldit education mode campaign features 49 levels grouped into 11 categories. The campaign has 6 new levels designed specifically for education mode and 4 levels adapted from the traditional Foldit campaign for use within education …

Structural And Functional Lessons Learned About Regulation Of Enterotoxigenic E. Coli Virulence Regulatory Factor, Rns, Jessica Dianne Tolbert

Dartmouth College Ph.D Dissertations

Antibiotic resistance has exacerbated the global health crisis of diarrheal diseases caused by enteric bacterial pathogens. Investigating pathogens, such as Enterotoxigenic Escherichia coli (ETEC) and Vibrio cholerae (cholera), helps to uncover mechanisms for the inhibition of virulence gene expression. A notable member of the AraC transcription factor family in ETEC, Rns, regulates virulence factors including pili and fimbriae, which are essential for adherence and colonization of the intestinal epithelial layer. This microbe–host interaction initiates the release of toxins, leading to the water and ion loss in clinically diagnosed as diarrhea.

In the canonical N-terminal domain of Rns, mutagenesis of the …

Effect Of Glycation On The Binding Interactions Of Serum Albumin And Silver Nanoparticles, Megan Kirk

Celebrating Scholarship and Creativity Day (2018-)

Nanoparticles are particles ranging from 1-100 nanometers in size. Most nanoparticles, upon contact with biological matrices, are immediately coated with proteins, forming the protein corona, which can alter the structure and function of proteins. Despite the tremendous advancement of nanotechnology over the last decade, the interactions of nanoparticles with proteins are not well characterized. This project investigates the effect of glycation on the binding interactions of HSA, the most abundant protein in human blood, with silver nanoparticles using various spectroscopic techniques. This is important because in diabetic patients, HSA is exposed to high concentrations of glucose over extended periods of …

A Qualitative Nmr And Histological Analysis Of Adipocere Formation In Different Aqueous Environments Using Sus Scrofa Models, Mia M. Sorrentino

Student Theses

Adipocere is a wax-like crust that has the potential to form over corpses in moist, humid, and anaerobic environments, preserving them in a process similar to that of mummification. The substance can be identified within 3-6 months postmortem and is characterized by the ratio of saturated fatty acids to unsaturated fatty acids. Palmitic acid and stearic acid are the most abundant in comparison to myristic and oleic acids. The goal of this study was to investigate factors affecting adipocere formation in different aqueous environments. Pork belly samples were submerged in water samples collected from different places around New York City …

Metabolic Transitions In Embryos Of Artemia Franciscana: Regulation And Consequences For Oxidative Stress, Daniel Anthony Arabie

LSU Doctoral Dissertations

Embryos of Artemia franciscana survive harsh conditions in diapause and anoxia-induced quiescence for years by undergoing deep metabolic transitions. I investigated the relationship between phosphorylation of pyruvate dehydrogenase (PDH) and carbon flux to the tricarboxylic acid (TCA) cycle during metabolic depression. The difference in catalytic activity of the PDH complex (PDC) in maximally phosphorylated and dephosphorylated samples was 16.5-fold. Western blot analysis confirmed the changes in phosphorylation of PDH. Analysis of PDH expression in diapause and post-diapause embryos via phospho-PDH showed no significant differences. Investigation of post-diapause embryos under anoxia showed that phosphorylation of PDH decreased and activated the enzyme. …

First-In-Class Peptide Molecules Targeting The Mien1 Cancer Signaling Pathway, For Which No Inhibitors Have Been Identified To Date., Amit Tripathi, Jamboor K. Vishwanatha

Research Symposium

Background: Migration and Invasion Enhancer 1 (MIEN1) is a critical oncogene that drives cancer cell migration, invasion, and epithelial-to-mesenchymal transition (EMT) in various cancers. MIEN1 overexpression is linked to aggressive tumor progression and poor prognosis. Despite its established role in cancer biology, targeted therapeutic options remain unexplored. This study aimed to identify and characterize first-in-class therapeutic molecules targeting the MIEN1 signaling pathway to inhibit cancer progression.

Methods: To develop novel bio-active peptides, we leveraged conserved immunoreceptor tyrosine-based activation motif (ITAM) and prenylation motifs within the MIEN1 protein sequence. Using rational peptide design, we identified and synthesized bioactive peptides, namely LA3IK …

Ivy Proteins As Guardians Of Bacterial Cell Wall Integrity: Regulation Of Lytic Transglycosylases Explored, Aamna Aijaz, Trinity E. Alamutu, Vy T. Dao, Nathaniel R. Davis, Michael D. Landers, Nykolas K. Mackevicius, Liliana Ortiz, Irina F. Padilla-Montoya, Kacy J. Smith, Maria L. Snyder, Anthony J. Stefanie, Blaise M. Williams, Thomas C. Leeper

The Kennesaw Journal of Undergraduate Research

Lytic transglycosylases (LTs) are bacterial enzymes involved in biosynthesis and maintenance of the peptidoglycan cell wall. LTs are reported to be regulated by two paralogs of Inhibitor of Vertebrate Lysozymes: Ivyp1 and Ivyp2. This study investigated the regulatory dynamics between the soluble LT (SltB1), and Ivy paralogs as putative regulators in Pseudomonas aeruginosa (PA). The secondary objective was to delineate the critical roles played by a glutamic acid at position 135 in SltB1 and a histidine at position 62 in Ivyp1 in governing their molecular interaction through site directed mutagenesis. Isolated SltB1 shows no lytic activity in our assay, in …

Fast 3d Printing Of Fine, Continuous, And Soft Fibers Via Embedded Solvent Exchange, Wonsik Eom, Mohammad Tanver Hossain, Vidush Parasramka, Jeongmin Kim, Ryan W. Y. Siu, Kate A. Sanders, Dakota Piorkowski, Andrew Lowe, Hyun Gi Koh, Michael F. L. De Volder, Douglas S. Fudge, Randy H. Ewoldt, Sameh H. Tawfick

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Nature uses fibrous structures for sensing and structural functions as observed in hairs, whiskers, stereocilia, spider silks, and hagfish slime thread skeins. Here, we demonstrate multi-nozzle printing of 3D hair arrays having freeform trajectories at a very high rate, with fiber diameters as fine as 1.5 µm, continuous lengths reaching tens of centimeters, and a wide range of materials with elastic moduli from 5 MPa to 3500 MPa. This is achieved via 3D printing by rapid solvent exchange in high yield stress micro granular gel, leading to radial solidification of the extruded polymer filament at a rate of 2.33 μm/s. …

Human Serum Albumin Interaction With Organochlorine Pesticides, D. S. Sanford, R. Yadav, A. Mishra

Journal of the Arkansas Academy of Science

Human serum albumin (HSA) is the most abundant blood plasma protein and plays a crucial role in drug transport and physiological homeostasis. HSA has a highly flexible structure consisting of three domains, each with multiple binding sites lined with hydrophobic and hydrophilic residues. The structural properties of HSA make it a robust reservoir and receptor for various endogenous and exogenous compounds, including therapeutic drugs. Organochlorine pesticides (OCPs) are a subclass of pesticides characterized by their chlorine content. Once widely used, these compounds remain persistent in the environment and biological systems despite regulatory restrictions in many developed countries. The strong ligand-binding …

Raman Spectroscopy For Rapid Quantification Of Macronutrients In Heirloom Beans, K. Chandler Williams

Graduate Theses, Dissertations, and Problem Reports (ETD)

Quantification of macronutrients in food requires a large investment in facilities and instrumentation as well as ongoing expenses of labor, reagents, and hazardous waste disposal. These costs pose a significant barrier to determining macronutrient quantities in the thousands of uncharacterized landrace and heirloom crops and discourage traditional crop breeding projects from ensuring that their selected crops maintain desirable macronutrient profiles in addition to target agronomic traits. Our objective was to test whether a hand-held Raman spectrometer—a technology which has found use in plant disease diagnostics but remains largely overlooked in nutrient quantification-- could provide a feasible means for quantifying the …