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 …

Identifying Textual Predictors Of Early Termination In Clinical Trials In Medicine: An Explainable Machine-Learning Study, Rohan Ramnarain

Dissertations, Theses, and Capstone Projects

About one in five clinical trials in medicine ends early, wasting valuable resources and reducing the evidence available for developing life-saving medical treatments. This project uses a method called Trial2Vec, which is a self-supervised machine-learning method that converts clinical trial documents into dense numerical representations that capture their key design and clinical characteristics, to turn each proposed clinical trial’s written protocol into a compact numerical profile (a process referred to as embedding). These profiles are then paired with a predictive machine learning models to identify the words and phrases in the trial documents that can signal a higher risk of …

Computational Insights Into Nucleosome Dynamics In Epigenetics Using Molecular Dynamics Simulations, Rutika Patel

Dissertations, Theses, and Capstone Projects

Nucleosome core particles (NCP) are the building blocks that form a highly organized and compact chromatin structure. Nucleosomes package DNA in the nucleus of eukaryotic cells. The NCP consists of about 147 base pairs of DNA wrapped around the histone octamer, with 1.65 superhelical turns in a left-handed manner. The histone octamer is composed of two copies of H3, H4, H2A, and H2B. Together with histone H1 and linker DNA, they further assemble into a higher-order chromatin structure. The nucleosome complex is stabilized by electrostatic interactions between positively charged histone residues and the negatively charged DNA backbone. To effectively access …

Supramolecular Assembly In Short Peptide Systems For Selective Metabolite Recognition And Drug Nanoencapsulation, Maithreyi Ramakrishnan

Dissertations, Theses, and Capstone Projects

Short peptides can form adaptive supramolecular assemblies, and understanding how minimal sequences organize around neurometabolites or hydrophobic cancer drugs enables the rational design of functional materials. This thesis combines molecular dynamics with experimental validation to establish design rules linking peptide sequence to emergent structure and function. Chapter 1 outlines the molecular determinants governing peptide assembly. Chapter 2 reviews computational workflows that reveal sequence-dependent conformations and supramolecular organization. Chapter 3 applies these principles to Dynamic Peptide Libraries which identify tetrapeptides that selectively interact with neurometabolites. Chapter 4 extends the same interaction-driven framework to design tryptophan-rich pentapeptides that co-assemble with kinase inhibitors …

Mapping Nucleosome Stability: Linking Oncogenic Structural Alterations To Long-Range Allosteric Communication, Augustine C. Onyema

Dissertations, Theses, and Capstone Projects

The nucleosome core particle (NCP) is essential for chromatin structure and function, serving as the fundamental unit of eukaryotic chromatin. Oncogenic mutations in core histones disrupt chromatin dynamics, altering DNA repair and transcription processes. How DNA communicates with histones, and how this information propagates through the histone, has been suggested to be a cooperative process. Here, I investigate the molecular consequences of two mutations, H2BE76K and H4R92T, using 36 µs of all-atom molecular dynamics simulations on Anton2. I also characterize the kinetic correlation within histone/DNA domains via conditional activity (CONDACT) using the dihedral angle as our degrees of …

Immunomodulatory And Signaling Molecules From Plant-Associated Bacteria: Toll-Like Receptor 4 Agonist Adjuvants And Diketopiperazine-Mediated Communication, Marian Romaine

Dissertations, Theses, and Capstone Projects

Medicinal plants and their associated microbiomes constitute a rich source of bioactive natural products with applications in immunotherapy and microbial ecology. Herbal formulations have long been valued for safe immune enhancement, while bacterial signaling molecules govern community behaviors critical to pathogenesis, symbiosis, and environmental processes. Bacterial lipopolysaccharides (LPS) from plant-associated Gram-negative bacteria have emerged as potent TLR4 agonists, yet their endotoxic potential limits direct use, and diketopiperazines (DKPs) serve as versatile quorum-sensing mediators capable of modulating biofilms in mixed microbial systems.

The work in this thesis comprises two independent but complementary research strands. The first strand pursued the engineering of …

Characterization And Advancement Of Molluscan Venom Gland Cell Model Systems, James V. Parziale

Dissertations, Theses, and Capstone Projects

Venomous mollusks, including cone snails and coleoid cephalopods, produce rich repertoires of bioactive peptides with profound effects on cellular physiology, yet there are few tractable experimental systems that exist to study their development, maintenance, and venom secretion. Although therapeutics such as the cone snail peptide Ziconotide demonstrate the biomedical potential of molluscan venoms, progress in understanding how venom glands form, function, and evolve has been hindered by the lack of reliable husbandry and the complete absence of in vitro cell models. Modern comparative genomics has revealed widespread convergent evolution across venomous lineages, but molluscan datasets remain underrepresented, limiting insights into …

Monosaccharide Binding To Synthetic Carbohydrate Receptor Microarrays, Milan A. Shlain

Dissertations, Theses, and Capstone Projects

Chapter 1: A glycan detection platform comprised of synthetic carbohydrate receptors (SCRs) immobilized onto polymer brushes was prepared. SCR043, an alkene-containing SCR, was incorporated into grafted-from polymer brushes using hypersurface photolithography, resulting in microarrays of SCR043-functionalized polymer brushes, where brush height (h) and SCR grafting density (Γ) is controlled precisely at each feature in the array. The influence of h and Γ on the binding to five fluorescently labelled monosaccharides – α-glucose (α-Gluc-FL), α-galactose (α-Gal-FL), α-mannose (α-Man-FL), β-glucose (β-Gluc-FL), and β-galactose (β-Gal-FL) – in aqueous buffer …

4e-Bp1 Differentially Regulates Translation Of A Subset Of Human Mrnas, Mehreen Mahbub

Dissertations, Theses, and Capstone Projects

Elevated levels of eukaryotic initiation factor 4E-binding protein 1 (4E-BP1) influence cap-independent translation by forming a complex with eukaryotic initiation factor 4E (eIF4E) (eIF4E•4E-BP1). Certain mRNAs—including those encoding hypoxia-inducible factor-1α (HIF-1α), fibroblast growth factor-9 (FGF-9), and two isoforms of tumor suppressors, p53 (p53_A, and p53_B)—contain structured 5’untranslated regions (UTRs) that enable translation either via cap-independent translation enhancer (CITE)-like or internal ribosomal entry site (IRES)-like mechanisms. However, how 4E-BP1 modulates these mechanisms remains unclear. Using fluorescence-based anisotropy assays, we showed that the eIF4E•4E-BP1 binds more tightly to the 5’ m⁷G-cap of these mRNAs than eIF4E …

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 …

The Sonic Hedgehog Effector Smoothened Modulates Cholinergic Interneuron Activity, Physiology, And Striatum-Dependent Behaviors, Santiago Uribe-Cano

Dissertations, Theses, and Capstone Projects

The striatum is a central node in action selection and associative learning, integrating cortical, thalamic, and neuromodulatory input. Among its principal modulators, dopamine (DA) and acetylcholine (ACh) are known for their temporally coordinated yet mechanistically distinct influences on striatal output. However, the upstream signals that regulate their dynamic interplay, particularly within cholinergic interneurons (CINs)—the primary source of striatal ACh—remain incompletely characterized. This dissertation investigates the role of Smoothened (Smo), a G protein-coupled receptor (GPCR) effector of Sonic Hedgehog (Shh) signaling, in modulating ACh signaling dynamics in the striatum.

Building on evidence that midbrain DA neurons co-release Shh and that CINs …

Mechanistic Insights Into The Neuroprotective Effects Of The Antidepressant Agomelatine In Alzheimer's Disease, Grace Terry

Dissertations, Theses, and Capstone Projects

Alzheimer’s Disease (AD) is a complex neurodegenerative disease that has limited treatment options and no cure. AD is characterized by robust pathology including extracellular amyloid beta plaques, intracellular neurofibrillary tangles, neuronal and synaptic loss, neuroinflammation, and brain atrophy. AD presents with cognitive decline and memory loss but only years after neuropathology has started to accumulate. This robust pathology has made AD difficult to treat and highlights the need for therapeutics that modulate multiple pathways. Agomelatine (AGO) was selected by a high-throughput machine learning drug repurposing algorithm by our collaborator Dr. Lie Xie (Hunter College Dept. of Comp. Sci.) as having …

Investigating The Role Of Early Growth Response 1 (Egr1) Gene In Riluzole-Induced Apoptosis In Osteosarcoma, Syeda Maryam Azeem

Dissertations, Theses, and Capstone Projects

Osteosarcoma is a rare but aggressive bone malignancy most commonly affecting adolescents and young adults (AYA). With 5-year survival rate stagnating over the last four decades despite the advancements in multi-modal therapy, drug repurposing offers a rapid path to new osteosarcoma treatments. Recent studies suggest that Riluzole, a drug approved for amyotrophic lateral sclerosis (ALS), may be repurposed for osteosarcoma treatment due to its ability to slow tumor progression and induce apoptosis. Previously, we have shown that Riluzole increases reactive oxygen species (ROS), activating c-Abl, which phosphorylates YAP in the nucleus. YAP then forms a complex with p73 to enhance …

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, …

Elucidating The Roles Of Eukaryotic Initiation Factors Involved In Dap5 Mediated Translation, Jacob Nk Quartey

Dissertations, Theses, and Capstone Projects

Translation initiation in eukaryotes is a highly regulated process essential for accurate protein synthesis. It is a dynamic process that involves a complex interplay between messenger RNAs (mRNAs), ribosomal subunits, and a host of initiation factors, ensuring precise start codon selection and the subsequent assembly of the translation machinery. This process has well been known to be mediated by the eukaryotic Initiation Factor (eIF4F), which consists of the cap binding protein eIF4E, the scaffolding protein eIF4GI, and the helicase factor eIF4A.The recognition and binding of eIF4E to the m⁷G cap structure of the mRNA is essential for the …

Biophysical Analysis Of S100a12 And The Nucleosome Core Particle, Christopher Diforte Jr.

Dissertations, Theses, and Capstone Projects

Calcium signaling and chromatin remodeling are fundamental regulatory processes that control protein activity and gene expression, respectively. This thesis investigates the molecular mechanisms by which local ligand binding and structural perturbations propagate allosteric effects across larger protein systems, using two distinct yet mechanistically analogous models: the calcium binding protein S100A12 and the nucleosome core particle. These studies are unified by a shared emphasis on how physical forces govern biological function.

In the first part, we explore calcium mediated allostery in S100A12, focusing on the distinct roles of its two EF-hand calcium binding loops (EF-I and EF-II). Through a combination of …

Structural Studies Towards The Mechanism Of Scanning And Initiator Trna Recruitment During Eukaryotic Translation Initiation, Da Cui

Dissertations, Theses, and Capstone Projects

The central dogma, proposed by Francis Crick in 1958, marks the direction of the flow of genetic information: from DNA to DNA (DNA replication), DNA to RNA (transcription), and RNA to protein (translation). Each of these is tightly regulated and important for cells and organisms to function correctly, grow, and reproduce.

In the eukaryotic system, the initiation stage of translation is the first, the rate-limiting, and the most regulated stage. It involves direct regulation of multiple eukaryotic initiation factors (eIFs), scanning factors such as DHX29, and other factors such as Poly-A binding protein (PABP). It starts with the small subunit …

The Role Of Secondary And Tertiary Structure In The Cap-Independent Translation Of Fgf-9 And Hif-1-Alpha, Amanda Michelle Whittaker

Dissertations, Theses, and Capstone Projects

Under normoxic conditions, eukaryotes initiate translation of RNA through eIF4E recognition of the 5’ cap. However, under cellular stress, eukaryotic translation must be initiated through a 4E-independent, or “cap-independent” mechanism, involving eukaryotic initiation factor 4G (eIF4G) binding directly to the 5’ untranslated regions (5’ UTR) of the RNA. eIF4G binding then recruits the ribosome to the transcript. While this mechanism is useful for translation of apoptotic transcripts and transcripts involved in cell survival, cap-independent translation is also utilized by oncogenic RNA for tumorigenesis. Previous work by our lab and others has categorized this recruitment and initiation mechanism as either internal-ribosome-entry-site …

Taming Biological Complexity Through The Use Of Symmetries, Luis A. Álvarez-García

Dissertations, Theses, and Capstone Projects

The study of biological systems is, inherently, the study of very complex systems. This is essentially due to the fact that they are made up of numerous, often very complicated, interactions between an extensive number of components. Often necessitating an abundance of quantitative parameters and details for a precise description. The human brain for ex- ample, consisting of ∼ 80 billion neurons with ∼ 800 to 100 trillion connections between them, each of them depending on a large set of parameters. Even simpler examples such as bacterial organisms, such as E. coli and B. subtilis, which we focus on …

Solvation Thermodynamic Mapping Approaches For Computer-Aided Drug Discovery, Vjay Molino

Dissertations, Theses, and Capstone Projects

The drug discovery process is inherently long and costly, prompting the development and integration of computational tools to mitigate these challenges. One of area explored in computer-aided drug discovery is to understand the role of solvation in protein-drug binding and to develop computational tools and methods that can be integrated in the drug discovery process. Grid Inhomogeneous Solvation Theory (GIST) is a tool that provides a framework for mapping solvation thermodynamiproperties of water molecules on the protein surface.This thesis explores the use of GIST in generating pharmacophore models and elucidates the role of solvation in protein structural fluctuations.

One of …

Incorporating Solvation Thermodynamic Mapping In Computer-Aided Drug Design, Yeonji Ji

Dissertations, Theses, and Capstone Projects

Advancements in computational techniques have revolutionized structure-based drug design, substantially improving the efficiency and effectiveness of the drug discovery process by reducing time, costs, and labor requirements. These advancements include various methods, such as investigating small molecule ligands binding to proteins, exploring alternative protein conformations, and solvation mapping on the protein surfaces. Among these methods, understanding the correlation between protein-ligand binding and the role of solvation is important.

A fundamental concept in protein-ligand binding is shape and electrostatic complementarity, which is complicated by the inherent flexibility of proteins. In the absence of small molecule ligands, proteins are complementary to surface …

Development Of Collagen Mimetic Mini-Fibrils With Tunable Collagenase Susceptibility, Jui Chaugule

Dissertations, Theses, and Capstone Projects

Collagen fibrils are the primary molecular scaffold of all connective tissues and provide the essential support for cell migration and differentiation. Collagen fibrils represent one of the most complex molecular hierarchies: three polypeptide chains in Gly-Xaa-Yaa repeating amino acid sequences, first form the rod-shaped collagen triple helix. These triple helices further self-assemble laterally in a specific manner to form fibrils having the characteristic 67 nm axially repeating structure known as the D-period. Enzymatic digestion of collagen fibrils by matrix metalloproteinases (MMPs) is critical for several physiological processes and is of particular consequence during wound healing. Many of the mechanisms of …

The Epigenetic Impact Of Dietary Choline On Growth Outcomes Of Children Exposed To Gestational Diabetes Mellitus, Ismail Kadam

Dissertations, Theses, and Capstone Projects

Maternal insulin resistance and hyperglycemia lead to gestational diabetes mellitus (GDM) which can cause fetal hyperinsulinemia, ultimately leading to excessive fetal growth associated with macrosomia and increased adiposity at birth. Increased placental macronutrient transport and epigenetic changes in growth and metabolic genes affected by GDM contribute to fetal overgrowth and can result in complications such as overweight/obesity, insulin resistance/type 2 diabetes, cardiovascular disease risk factors, as well as cognitive impairment later in life. Choline, an essential nutrient, participates in lipid and energy metabolism by providing methyl groups for DNA methylation and thus may overcome the hypomethylation of growth and metabolic …

Voltage Set Points For Sodium Channel Inactivation: Intrinsic And Modulatory Mechanisms, Akshay Sharma

Dissertations, Theses, and Capstone Projects

During an action potential, voltage-gated sodium channels (VGSC) control sodium ion flow into the cytoplasm of cells by using membrane voltage to alter channel conformation. These membrane proteins exhibit three main functional conformations: closed, open, and fast-inactivated, with transitions between these states dependent on membrane voltage and kinetics. The channels open within 1 millisecond and swiftly transition from open to fast-inactivated within 1-2 milliseconds following membrane depolarization. Subsequent membrane repolarization resets the channels to the closed state. Notably, even at mildly depolarized potentials that preclude channel opening, VGSCs can undergo transitions between the closed and inactivated states, known as closed-state …

Newly Synthesized Pyroglutamate Amide And Its Neuroprotective Effect Against Neurotoxicity Induced Cell Death In Alzheimer's Disease, Nourelhouda Joutey Elamrani

Dissertations, Theses, and Capstone Projects

The neurodegenerative disorder is an umbrella term for a range of conditions that affects the neurons in the human brain causing neuronal cell death. The common pathway is the excitotoxicity, a phenomenon that describes the toxic actions of excitatory neurotransmitters, primarily glutamate, where the exacerbated or prolonged activation of glutamate receptors starts a cascade of neurotoxicity leading to the cell death. One of the most common neurodegenerative disorders is Alzheimer’s disease (AD), which represents 60 – 70% of cases and it ranked fourth cause of mortality in the USA. In Alzheimer’s disease, glutamate released from astrocytes and activates extrasynaptic N-methyl-D-aspartate …

Exploiting The Heavy Chain Glycans For The Improvement Of Radioimmunoconjugates, Cindy Rodriguez

Dissertations, Theses, and Capstone Projects

Radiolabeled antibodies have become indispensable tools in nuclear medicine. However, the natural roles of antibodies within the immune system mean that they have several intrinsic limitations as a platform for radiopharmaceuticals. A handful of recent preclinical studies suggest that binding by FcR and particularly FcyRI can affect the pharmacokinetic profiles of 89Zr-labeled radioimmunoconjugates. Fc receptors (FcR) are responsible for many of the interactions between immunoglobulins (IgG) and immune cells. In biomedicine, this interplay is critical to the activity of several types of immunotherapeutics; however, relatively little is known about how FcRs affect the in vivo performance of radiolabeled antibodies. Antibodies …

Development Of Platinum(Iv)-Gold(I)-Based Anticancer Agents, Javier E. Lopez-Hernandez

Dissertations, Theses, and Capstone Projects

Heterometallic compounds have emerged as prospective multitarget anticancer drugs. These species may display improved efficacy and physicochemical properties compared to the individual metallic fragments, while helping combat drug resistance by exerting effects on multiple pathways. In this thesis we describe the synthesis of new bi- and tri-metallic compounds based on platinum(IV) compounds containing FDA-approved platinum agents, and gold(I) derivatives with known anticancer properties. We demonstrate their toxicity and selectivity against a small panel of renal, bladder, ovarian, and breast cancer cell lines, as well as their synergistic effects. We have selected a trinuclear PtAu₂compound containing the Pt(IV) core …

Positron Emission Tomography In Oncology And Environmental Science, Samantha Delaney

Dissertations, Theses, and Capstone Projects

The last half century has played witness to the onset of molecular imaging for the clinical assessment of physiological targets. While several medical imaging modalities allow for the visualization of the functional and anatomical properties of humans and living systems, few offer accurate quantitation and the ability to detect biochemical processes with low-administered drug mass doses. This limits how physicians and scientists may diagnose and treat medical issues, such as cancer, disease, and foreign agents.

A promising alternative to extant invasive procedures and suboptimal imaging modalities to assess the nature of a biological environment is the use of positron emission …

Mechanistic, Biochemical, And Theoretical Studies Of Phototoxicity And Photobluing, Lloyd M. Lapoot

Dissertations, Theses, and Capstone Projects

This thesis consists of four chapters as detailed below:

Chapter 1 discusses the photoconversion of heptamethine to pentamethine cyanines and of pentamethine to trimethine cyanines. Here, we report mechanistic studies and initial experimental evidence for a previously unexplored 4-carbon truncation reaction that converts the simplest heptamethine cyanine to the corresponding trimethine cyanine. We propose a DFT-supported model describing a singlet oxygen (¹O₂) mediated formation of an allene hydroperoxide intermediate and subsequent 4-carbon loss through a retro-Diels-Alder process. Fluorescence and mass spectrometry measurements provide evidence for this direct conversion process. This 4-carbon truncation reaction adds to growing …