Biochemistry, Biophysics, and Structural Biology Commons^™

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 …

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 …

Decoding The Allosteric Grammar Of Protein Kinases: A Dual-Stream Framework Integrating Protein Language Models And Energy Landscape Frustration Analysis, Will Gatlin, Max Ludwick, Lucas Turano, Brandon Foley, Kamila Riedlova, Vít Škrhák, Marian Novotný, David Hoksza, Gennady M. Verkhivker

Mathematics, Physics, and Computer Science Faculty Articles and Research

The spatial and energetic encoding of allosteric regulatory sites remains a major challenge in structural biology, frequently representing a “blind spot” for sequence-based artificial intelligence (AI) models. We present a protein language model (PLM)-guided approach complemented by the energy landscape frustration analysis as a dual-stream framework to investigate the relationship between AI prediction of binding sites and biophysical organization of regulatory pockets across the human kinome. By probing a fine-tuned residue-level PLM classifier across 453 kinase structures, a clear performance gap is discovered between highly predictable orthosteric pockets (Types I, I.5, and II) and poorly resolved distal allosteric sites (Type …

Structure-Based Discovery Of Malate Dehydrogenase Inhibitors With Efficacy Against C. Parvum Oocysts, Ankita Bharatbhai Kheni

Biochemistry and Molecular Biology

Cryptosporidium parvum, the etiological agent of Cryptosporidiosis (diarrheal illness) represents a significant global health burden, particularly affecting immunodeficient and pediatric populations. Since the parasite has a highly reduced mitochondrion and relies on glycolysis, enzymes such as C. parvum malate dehydrogenase (CpMDH), which are believed to be indispensable for parasite viability due to their pivotal roles in NAD⁺ regeneration and redox balance, remain largely unexplored as therapeutic targets. The present study employed a multifaceted experimental and computational strategy to evaluate the inhibitory activity of two lead-like and drug-like small molecules, referred to as compound 1.8 and compound 1.5, against the cofactor …

Developing A Protocol For Non-Cellular Transplantation Of Donor Mitochondria Into Recipient Cells, Andrew Parton

Honors Theses

Tumor innervation has emerged as a critical feature of cancer progression, with increased nerve density correlating with enhanced aggressiveness, metastatic dissemination, and poor clinical outcome. However, the functional contribution of neurons to tumor biology remains incompletely defined. We recently identified the intercellular transfer of mitochondria from neurons to cancer cells as a mechanism that promotes tumor progression. We therefore hypothesized that disruption of this transfer could attenuate tumor aggressivity. To directly investigate this process, we developed an approach to isolate mitochondria from donor cells and transplant them into recipient cancer cells independently of canonical cell-cell interactions. Transferred mitochondria were tracked …

Genome-Wide Phenotypic Characterization Of Mycobacteriophage Mercurio, Tyler Downs

Departmental Honors & Graduate Capstone Projects

Bacteriophages, or phages, are being piloted as a supplemental or alternative therapeutic to antibiotics against drug-resistant Mycobacterium pathogens, such as M. tuberculosis, which pose a global public health crisis.  Characterizing bacteriophage genomes can provide insights into efficacy in phage therapy before implementation or elucidate new targets to manipulate bacterial growth.  Overexpression of individual phage genes is useful to study a gene product’s function independent of others.  Here, the results of phage Mercurio plasmid library overexpression in plate-based assays are described.  Mercurio infects nonpathogenic Mycobacterium smegmatis and is genetically related to bacteriophages infecting pathogenic Mycobacterium species.  Eleven gene products of …

Comparative Biomechanics: Blattodea Antennal Morphology And Physiology, Lucas W. Marsh

All Theses

Equipped with muscle-free antennae, many insects can twist and bend their antennae on demand. We hypothesized that hemolymph circulating through the antennae provides pressure that facilitates twisting and bending and provides a feedback control channel for tactile sensing in insects. To test this hypothesis, we conducted a thorough morphological and physiological analysis of antennae in three Clades of Blattodea. We studied morphology by evaluating the distinguishable features of the body and antenna, as well as the internal structure of the antennal lumen. Then, in a series of experiments on live cockroaches, we measured blood pressure along the antenna. This was …

Membrane Organization Of Rheb And Rhoa: Roles In Function And Allosteric Druggability, Chase M. Hutchins

Dissertations and Theses (Open Access)

Small GTPases of the Ras superfamily are membrane-bound molecular switches that regulate nearly all major cellular processes, and their dysregulation drives cancers, neurological disorders, and metabolic diseases. While anchored to cellular membranes, the catalytic domains of small GTPases undergo orientation dynamics, adopting distinct configurations that can occlude or expose effector-binding surfaces and modulate signaling output. These dynamics have been characterized in the Ras oncoproteins, but whether they extend across the superfamily and influence allosteric druggability has remained unknown.

In this dissertation, I address these questions through Rheb and RhoA, two small GTPases with complementary differences in subfamily lineage, membrane localization, …

Understanding The Role Of Toxs As A Bile Sensing Component Of The Toxrs Virulence Regulatory System In Vibrio Spp., Minje Kim

Dartmouth College Ph.D Dissertations

Pathogenic Vibrio bacteria, such as V. cholerae and V. parahaemolyticus, colonize in the human small intestine to cause severe gastrointestinal disease. During the infection, these bacteria encounter bile salts, antimicrobial cholesterol metabolites secreted into the intestine. Pathogenic Vibrio species have evolved to utilize bile salts as signals to regulate virulence. The signaling depends in part on ToxRS, a conserved co-component transmembrane transcription regulator. ToxRS consists of the transcription factor ToxR and its membrane-tethered binding partner ToxS. ToxS is required for ToxR stability and full transcriptional activity. Although bile salts are known to influence ToxRS-dependent virulence gene expression, the molecular …

Spin-Label Probing Of Gp28 Elucidates Interactions With Lipid Vesicles Using Cw-Epr, Maxwell Sutherland, Binaya Baral, Gary Lorigan

ONU Student Research Colloquium

The phage protein gp28 is a bacterial membrane lysis protein that functions outside of currently understood canonical pathways for bacterial lysis. Primarily, lysis is done in conjunction with proteins called spanins, however about 15% of gram negative bacteria infecting phages have coding for spanins. This led to the discovery of the disruptins, a class of non-spanin outer membrane disrupting proteins which includes gp28 from the φKT phage. To understand the mechanism in which gp28 disrupts the outer membrane, we employ spin labeling of the protein in its synthesis and create samples of artificial membranes. Using electron paramagnetic resonance (EPR), we …

G-Quadruplex Dna-Driven Genomic Instability Under Ber Loss, Addison Belick, Claryssa Gutierrez, Joslynn Rosas, Andrea Vargas

Posters - 2026

Base Excision Repair (BER) is a cellular tool that can repair damaged DNA (Hindi et al., 2022, Cellular and Molecular Life Sciences). G-quadruplexes (G4s) are unique 4-stranded structures in DNA or RNA that are rich in guanine (Gray et al., 2023, Nat. Chem. Biol). The purpose of this study is to understand whether BER contributes to the removal of G4s in DNA. This will determine if the BER-deficient yeast is more sensitive to treatment with G4-binding drugs than the BER-proficient yeast. We will replace the APN1 gene in the yeast genome with the URA3 gene, because the wild type yeast …

Investigating Rad14 Gene Nucleotide Excision Repair On G-Quadruplexes, Juan Pablo Olvera Rodriguez, Tyna Trevino, Yvette Gonzalez, Georgia Romike

Posters - 2026

DNA is typically found as a double-stranded helical structure; however, it can be found in different types of structures, such as G-quadruplexes (G4s). These are structures formed when DNA sequences are rich in Guanines, which interact with each other by hydrogen bonding, forming stacked G-tetrads. These guanine-rich structures are known for interacting with DNA during important cell processes, such as recombination and replication, leading to instability and DNA damage (Grey et al., 2014). If not treated properly, these structures may contribute to mutations and cancer development. To solve these issues, cells have developed maintenance pathways such as Nucleotide Excision Repair …

Morphological Characteristics Of The Mediophyceae Diatom Lampriscus Cf. Shadboltianus Var. Crenulatus Collected From Gili Meno, Indonesia, Arief Rachman, Riani Widiarti, Setiarti Sukotjo, Mark Wells

Makara Journal of Science

Diatoms are the most common and abundant microalgae group in seawater, with an estimated 200 genera and 200,000 species categorized into three distinct taxonomic classes: Mediophyceae, Bacillariophyceae, and Coscinodiscophyceae. This study describes the morphological characteristics of Lampriscus GM052022, a diatom belonging to the Mediophyceae family, which was collected from Gili Matra, Lombok, Indonesia. Analysis using light microscopy (LM) and electron microscopy (EM) showed that the morphological characteristics of the Lampriscus GM052022 specimen are similar to those of Lampriscus shadboltianus var. crenulatus due to the distinct crenulation lines on the frustule, which differentiate this variation from Lampriscus shadboltianus. However, the …

Development Of An Ied Response Model For Testing Of The Snapping Shrimp Resource Allocation Algorithm, Joanna Morris

Student Research Symposium (SRS)

"Models must be capable of demonstrating adaptability across multiple case studies to confirm their reliability and versatility. The Snapping Shrimp Resource Allocation Algorithm, which has been successfully applied in a wildfire response scenario, models efficient, decentralized coordination inspired by the behavior of snapping shrimp. Building on this foundation, the current work explores the potential application of the Snapping Shrimp Resource Allocation algorithm to improvised explosive device response where rapid, autonomous coordination could significantly enhance safety and operational efficiency. Improvised explosive devices remain a persistent issue in modern conflict, requiring strategies for response that are cost-effective, scalable, and capable of adapting …

Computational And Functional Characterization Of Terebrid Venom Peptides, Favour T. Achimba

Dissertations, Theses, and Capstone Projects

Venom peptides represent a natural repertoire of bioactive compounds that are potent modulators of ion channels. Teretoxins, venom peptides from terebrid snails, remain underexplored despite their structural and functional diversity. This thesis is the first to comprehensively explore the structure and function of teretoxins using a comparative computational sequence and structure model followed by experimental assays. The majority of the functional focus has been on identifying the ion channel molecular targets of uncharacterized teretoxins. Teretoxins, like other venom peptides, are hypothesized to manipulate the cellular function of a diversity of ion channels. Dysregulation of ion channels leads to several …

Protein Allostery Probed By Ligands Across Sites, Virgil A. Woods

Dissertations, Theses, and Capstone Projects

Allostery is a pervasive regulatory principle throughout biology, yet the structural pathways by which distal inputs alter active‑site chemistry within protein structures remain incompletely defined and exploited. This dissertation uses protein tyrosine phosphatase 1B (PTP1B) as a tractable model to map those pathways with complementary experimental and computational tools. I integrate high‑resolution hydrogen-deuterium exchange mass spectrometry (HDX-MS), room-temperature crystallography, NMR, steady-state kinetics, crystallographic pseudo-ensembles, and machine-learning-guided ligand discovery. The working premise is that regulation reflects redistribution within a conformational ensemble rather than a binary switch. That orthogonal perturbations by small molecules, mutations, and protein partners can be used to both …

Dapagliflozin Attenuates Cisplatin-Induced Nephrotoxicity In Rats Through Modulation Of Ros/Nf-Κb, Bcl2/Bax And Pink1/Parkin Signaling Pathways, Esraa K. Khallaf, Eman A. Ramadan, Mohey M. Elmazar, Marwa M. Safar

Pharmacy

Dapagliflozin (DPG), an anti-diabetic drug, has gained attention for its renal protective effects through multiple molecular pathways, yet its impact on mitophagy in cisplatin (CIS) nephrotoxicity remains unclear. This study aimed to examine the impact of DPG against CIS-induced nephrotoxicity in rats, targeting mainly PINK1/Parkin-mediated mitophagy and inflammatory/apoptotic pathways. Male Sprague Dawley rats received DPG (10 mg/kg; p.o) daily for 14 consecutive days and AKI was induced by a single injection of CIS (7 mg/kg; i.p) on day 10. Blood glucose, serum levels of creatinine and urea nitrogen, oxidative stress, inflammatory, apoptotic, mitophagy markers, and histological changes were assessed. DPG …

Potential Environmental Triggers Of Goodpasture's Disease And The Role Of The Sulfimine Crosslink, Colton S. Miller, Andrea Florian, Elena Pokidysheva

SPARK Symposium Presentations

Goodpasture’s syndrome (GP) is an autoimmune disorder that primarily affects kidneys and lungs. The main issue for patients with Goodpasture's syndrome is the binding of autoantibodies to the glomerular basement membrane (GBM), which hinders the filtration of blood. A key characteristic of Goodpasture's syndrome is the presence of autoantibodies that target the NC1 domain of the α345 isoform of type IV collagen, a crucial component of the GBM that provides structural support and is critical for filtration function. Sulfilimine bonds crosslink the collagen IV NC1 hexamers, contributing to the stabilization of these structures. A recent clinical case of recurring Goodpasture's …

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 …

A Framework For Characterizing The Peripheral Immune Isonome Using Long-Read Single-Cell Rna Sequencing And Its Relevance To Neurological Disease, Patricia Hayes Doyle

Theses and Dissertations--Neuroscience

Long-read single-cell RNA sequencing provides an opportunity to understand human health and disease at isoform resolution, revealing cellular diversity and disease mechanisms difficult to resolve with bulk or short-read methodologies.

Using a modified PIPseq workflow and computational pipeline adapted for Oxford Nanopore (ONT) sequencing, we profiled isoform usage across immune cells, integrating marker expression and isoform discovery, generating the largest long-read single-cell dataset of human immune cells from a single individual to date. We identified non-canonical protein-coding variants of GZMB and CD3G enriched in unexpected cell types. We also discovered novel transcripts from CMC1 and LYAR with cell-type-specific signatures that …

Exploring The Limitations Of Substrate Scope In Dimethylallyltryptophan Synthases, Evan T. Miller

Theses and Dissertations--Pharmacy

Natural products (NPs), are the largest source of bioactive compounds in Nature, and are essential to the treatment of human disease. Nearly 50% of drugs approved for use from 1981 to 2019 owe some aspect of their development to NPs, either in terms of their structure, pharmacophore, or mechanism of action. However, NPs are difficult to structurally optimize. Chemoenzymatic methods for NP derivatization have been increasingly seen as practical alternatives to traditional synthetic methods. Prenyltransferases (PTs) are involved in the primary and secondary metabolism of plants, bacteria, and fungi, and they are key enzymes in the biosynthesis of many clinically …

Systematics Of Disk-Winged Bats (Thyroptera), Courtney L. Klumpp

Capstone Showcase

This thesis investigates the evolutionary relationships among disk-winged bats in the genus Thyroptera, a small group of Neotropical bats known for the adhesive suction disks on their wings and feet that allow them to roost inside tightly rolled leaves. The distinctive morphology and behavior of these bats have not been extensively documented, and their phylogenetic relationships remain only partially resolved. The goal of this research is to better understand how these species are related to one another and to determine whether the five recognized species of Thyroptera form a single monophyletic group. To address this question, morphological and genetic …

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, …

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 …

Structural Basis Of A Class Ii Ribonucleotide Reductase Found If Mycobacterium Tuberculosis, Leah Jacob

Student Scholar Symposium

Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb), remains a leading global health challenge, particularly due to its ability to enter a dormant, drug-tolerant state that enables long-term persistence within the host. Just before dormancy, Mtb replicates its entire genome creating DNA precursors for when the infection reactivates. Ribonucleotide reductases (RNRs) play a critical role in bacterial survival by catalyzing the conversion of ribonucleotides into deoxyribonucleotides, a necessary step for DNA replication and repair. The class II RNR, NrdZ, has been implicated in facilitating Mtb persistence under hypoxic stress conditions, yet its structural and mechanistic function remains largely uncharacterized. …

Context Dependent Regulation Of Dicer Function During Oocyte-To-Embryo Transition, Nick A. Newkirk

Dissertations and Theses (Open Access)

Over two decades ago, Dicer was discovered as the primary enzyme responsible for the generation of small RNAs known as the microRNAs (miRNAs) and short interfering RNAs (siRNAs). Spatiotemporal regulation of Dicer-dependent small-RNA biogenesis affects many aspects of biology, including aging, disease progression, fertility, and cancer. Interestingly, a distinct population of Dicer-dependent small RNAs, known as the endogenous siRNAs (endo-siRNAs), are uniquely abundant in the germ cells and gametes, and are critical for normal fertility. Despite their function regulating new life, the mechanisms controlling their biogenesis and subsequent germ cell functions remain poorly defined. Work to parse these mechanisms in …

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, …

Role Of Nucleic Acids As Chaperones In Protein Folding, Zijue Huang

Electronic Theses and Dissertations

Many proteins have slow folding times in vitro that are physiologically untenable. To combat this challenge, ATP-dependent chaperonins are thought to possess the unique ability to catalyze protein folding. Performing quantitative model selection using protein folding and unfolding data, we here show that short nucleic acids containing Gquadruplex (G4) structure can also catalyze protein folding. Performing the experiments as a function of temperature demonstrates that the G4 reshapes the underlying driving forces of protein folding. To understand the structural basis of this catalytic activity, we introduce NMR method to solve the structures, at base-level resolution, of a multiconformer G4 with …

Claudin-1-Mediated Signaling And Therapy Resistance In Colorectal Cancer: From Mechanism To Translation, Mark W. Primeaux

Theses & Dissertations

Colorectal cancer (CRC) remains a leading cause of cancer-related mortality, with metastatic cases showing poor response to chemotherapy due to both intrinsic and acquired therapy resistance. Claudin-1 (CLDN1), a tight junction protein, is overexpressed and mislocalized outside of tight junctions in CRC, where it contributes to an aggressive, metastatic phenotype. Although this causal relationship has been well established, the mechanisms by which CLDN1 promotes tumor progression were unclear due to its lack of intrinsic enzymatic activity. This dissertation investigates the molecular mechanisms through which CLDN1 drives oncogenic signaling, its role in therapy resistance, and its translational potential as both a …

Development Of A Cure In Principles Of Cell And Molecular Biology, Heather Seitz

Sabbatical Projects

This project presentation highlights the work done during sabbatical to develop an authentic research experience into BIOL135 Principles of Cell and Molecular Biology. The sabbatical allowed for development time but further work was done to measure impact and outcomes for future implementation.