Biochemistry, Biophysics, and Structural Biology Commons^™

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 …

Benzothiazole Sulfones As A Tool For Peptide Modification And Cleavage, Phoebe R. Rubiio, Gavin A. Clausen, Zachary D. Ruighaver, Abigail F. Dalton, John P. Blobe, Amanda L. Moore, Christopher R. Shugrue

Chemistry Faculty Publications

We report the development of a new benzothiazole sulfone (BTS) tool for peptide modification and cleavage. Benzothiazole sulfones are electrophiles that rapidly react with thiols in nucleophilic aromatic substitution (SNAr) reactions. Alkyne-containing BTS compounds were incorporated onto azidolysine-containing peptides through copper-catalyzed azide-alkyne cycloadditions (CuAACs). BTS-containing peptides were found to react rapidly with two equivalents of thiol nucleophiles at room temperature in 30 min or less. BTS-containing peptides were conjugated to a variety of different compounds, including small molecules, fluorophores, and peptides. Alternatively, a BTS-based cleavable linker could also be synthesized with small molecule cargo, such as biotin, and …

Study Of Nano-Bio Interactions In Biological Fluids: Modelling And Simulations., Beatrice Cipriani

Doctoral

Nanoparticles have attracted significant interest due to their tunable properties and unique physicochemical characteristics, offering promising applications in drug delivery, biosensing, and diagnostics. Their use in medicine has the potential to reshape current paradigms by enabling more efficient, precise, and patient-centric approaches. Although advances in nanomaterial synthesis have rapidly expanded the library of available nanodevices, our understanding of the mechanisms that govern their behaviour at biological interfaces remains limited. Nanoparticles are similar in size to biomolecules found in biological environments, leading to complex, competitive interactions that affect their functional performance, biological fate, and acquired bioidentity. Unlike traditional small molecules, which …

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 …

Characterization Of Ru(Ii) Polypyridyl Photosensitizers Bound To Tio2 Supports Through A New Covalent Metal-Ester Bonding Motif, D. M. S. C. Dissanayake, Christopher T. Lebarron, Laura C. Maybach, Joseph J. Kuchta Iii, Seyyedamirhossein Hosseini, Aaron K. Vannucci

Faculty Publications

The development of photoelectrochemical (PEC) devices involves the attachment of molecular photosensitizers onto solid supports. Particularly significant to this work are PECs that rely on ruthenium-based photosensitizers on high band gap metal oxide (MOx) supports. In this study, we have explored a new ester binding motif (MOx-ester) to covalently attach a ruthenium polypyridyl photosensitizer to TiO₂. This new MOx-ester photoanode is compared to the traditional photoanodes that utilize acid/base binding groups to attach the molecular Ru sensitizers to TiO₂. The new MOx-ester binding motif is characterized by cyclic voltammetry UV-Vis, solid state ¹³C NMR, and …

An Antioxidant Cocktail Of Tert-Butylhydroquinone And A Manganese Porphyrin Induces Toxic Levels Of Oxidative Stress In Cancer Cells, Sandra Tamarin, Hannah Jung, Joseph Lamorte, Laura Biesterveld, Gabriel Piñero, Grace Turchetta, Molly Myers, Rebecca Oberley-Deegan, Aimee Eggler

Student Papers, Posters & Projects

Despite significant advancement in cancer treatments, therapies with minimal toxicity to healthy cells are still limited. One targetable weakness of cancer cells is their sensitivity to oxidative stress. We find that the combination of two antioxidants—the common food additive tert-butylhydroquinone (tBHQ) and a manganese porphyrin in clinical trials, MnTnBuOE-2-PyP5+ (MnBuOE)—increases oxidative stress and causes apoptotic death in several cancer cell lines, but not in mouse primary fibroblasts. Investigating the mechanism of cell death, MnBuOE is observed to catalyze the oxidation of tBHQ, producing the electrophilic quinone tert-butylquinone (tBQ). A critical role for tBQ and its electrophilic character was revealed with …

Oral Streptococcus And Vitamin B12 Deficiency In E-Cigarette Users: A Microbial–Nutrient–Neurotransmitter Axis Linking To Mood Disturbances, Maryam Sabah Naser, Ali Jabbar Abd Al-Hussain Alkawaz, Ali Abbas Hashim Almusawi, Ali Jalil Obaid, Hasanain Ayed Mohammed Al-Khafaji, Reihaneh Sabbaghzadeh

Karbala International Journal of Modern Science

Background: With the rising popularity of e-cigarettes, questions have emerged regarding their broader influence on oral ecology, nutrient absorption, and psychological health. Disruptions in the oral microbiome may alter vitamin B12 dynamics. This, in turn, may indirectly influence serotonin biosynthesis and mood regulation.

Methods: An observational cross-sectional study involved 150 young adults segregated into groups of 50 each as vapers, smokers, or non-users. Streptococcus sanguinis and vitamin B12 metabolism-related variable statuses methylmalonic acid and holotranscobalamin were quantified in samples, along with inflammatory markers interleukin-6, kynurenine/tryptophan ratio, and serotonin. Statistical techniques, including ANOVA and the Kruskal-Walli’s test, correlation, and serial mediation …

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 …

Chasing Disinfection Byproducts Through The Pipes: How 66 Dbps Change Over Time In Chlorinated Vs. Chloraminated Distribution Systems, Erik Niehaves, Patrick T. Justen, Ashley A. Perkins, Alexandria L.B. Forster, Caroline O. Granger, Susan D. Richardson

Faculty Publications

While disinfection byproducts (DBPs) are typically measured at drinking water treatment plants, levels can change dramatically within the distribution system before reaching the consumer. In this study, the spatio-temporal trends of 66 DBPs across 9 different classes were examined in two drinking water distribution systems with similar source waters, but different pretreatments and residual disinfectants. One system uses residual chlorine in the distribution system, and the other uses chloramine, allowing for examination of how DBP concentrations change over time in distribution systems with different residual disinfectants. Four routes were sampled for each system with six time points over three days …

Optimized Photoemission From Organic Molecules In 2d Layered Halide Perovskites, Muhammad S. Muhammad, Dilruba A. Popy, Hamza Shoukat, John M. Lane, Neeraj Rai, Vojtěch Vaněček, Zdeněk Remeš, Romana Kučerková, Vladimir Babin, Chenjia Mi, Yitong Dong, Mark D. Smith, Novruz G. Akhmedov, Daniel T. Glatzhofer, Bayram Saparov

Faculty Publications

In recent years, hybrid organic–inorganic metal halides have been at the forefront of materials research. Typically, the functional (e.g., optoelectronic) properties of hybrid halides are derived from the inorganic structural part, whereas the organic structural units can add extra advantages in terms of stability, rigidity, and processability. Here, we report the design, synthesis, and characterization of two new hybrid materials in which the outstanding photophysical properties originate from the organic structural part. The new compounds, (C₁₅H16N)₂CdCl₄ and((Br)C₁₅H₁₅N)₂CdCl₄, have 2D layered Ruddlesden–Popper-type perovskite structures. These hybrids are blue-white …

Defining Rna Oligonucleotides That Reverse Deleterious Phase Transitions Of Rna-Binding Proteins With Prion-Like Domains., Lin Guo, Jacob Mann, Jocelyn Mauna, Katie Copley, Hejia Wang, Jack Rubien, Cristian Bergmann, Jenny Carey, Jessica Merjane, Marilyn Ngo, Jiazhen Xu, Hana Odeh, Jiabei Lin, Bo Lim Lee, Laura Ganser, Emma Robinson, Kevin Kim, Anastasia Murthy, Tapas Paul, Bede Portz, Amanda Gleixner, Zamia Diaz, Ashleigh Smirnov, George Padilla, Ellen Lavorando, Carolann Espy, Yulei Shang, Eric Huang, Alessandra Chesi, Nicolas Fawzi, Sua Myong, Christopher Donnelly, James Shorter

Department of Biochemistry and Molecular Biology Faculty Papers

RNA-binding proteins (RBPs) with prion-like domains (PrLDs), such as FUS and TDP-43, condense into functional liquids, which can transform into pathological fibrils that underpin fatal neurodegenerative disorders, including amyotrophic lateral sclerosis (ALS)/frontotemporal dementia (FTD). Here, we define short RNAs that prevent FUS fibrillization by promoting liquid phases and distinct short RNAs that prevent and reverse FUS condensation and fibrillization. These activities require interactions with multiple RNA-binding domains of FUS and are encoded by RNA sequence, length, and structure. We define a short RNA that dissolves cytoplasmic FUS aggregates, restores nuclear FUS, and mitigates FUS toxicity in optogenetic models and ALS …

Structural Characterization Of Peptide Nanoaggregates At Varying Concentrations And Their Impact On Cellular Responses, Malika Rozmetova

Theses and Dissertations

Peptide nano-assemblies can regulate cellular pathways in a structure-dependent manner. Here, we show that the enzyme-responsive peptide NapFFK(NBD)Yp forms distinct nanoscale assemblies at different concentrations, triggering differential ER stress and extracellular vesicle release in MDA-MB231 cells. These results highlight the importance of supramolecular organization in peptide–cell interactions.

Flux Crystal Growth Of Potassium Lanthanide Double Vanadates With Lanthanide-Dependent Coordination Number Variance, Hunter B. Tisdale, Hans Conrad Zur Loye

Faculty Publications

A series of potassium rare earth double vanadates is presented. Single crystals of double vanadates with stoichiometry K₃Ln(VO₄)₂ (Ln = La, Pr, Nd, and Sm) and crystallizing in the glaserite structure type were synthesized via a molten alkali chloride/fluoride flux reaction. Different structures were observed depending on the constituent rare earth: K₃La(VO₄)₂ crystallizes in an as-of-yet unreported modification of the typical glaserite structure in the space group P2₁/c, likely due to its larger ionic size that results in an increase in the lanthanide coordination number …

Protocol For Stable Isotope Tracing Of Primary Human Peripheral Blood Mononuclear Cells, Samantha N. Hart, Holden C. Williams, William B. Inabnet Iii, Joshua P. Steiner, Varun Jain, Philip A. Kern, Cecily R. Wood, Barbara S. Nikolajczyk, Lance A. Johnson

Molecular and Cellular Biochemistry Faculty Publications

Stable isotope tracing gives direct insight into the rate of metabolic reactions occurring in cells by analyzing the incorporation of labeled carbons into metabolic pathways. Here, we present a protocol for stable isotope tracing of primary human peripheral blood mononuclear cells (PBMCs). We describe the steps for culturing and exposing PBMCs to stable isotopes U¹³C glucose and U¹³C glutamine. We then detail procedures for derivatization, metabolite purification, and tracing analysis via single-quadrupole gas chromatography-mass spectrometry (GC-MS).

A Live Cell Biosensor Protocol For High-Resolution Screening Of Therapy-Resistant Cancer Cells, Viral D. Oza, Colin S. Williams, Jessica S. Blackburn

Molecular and Cellular Biochemistry Faculty Publications

The Genetically Encoded Death Indicator (GEDI) is a ratiometric, dual-fluorescence biosensor that enables real-time detection of cell death through calcium influx. Originally developed for use in neurodegeneration models, GEDI can be applied to cancer cells to quantify therapy-induced death at single-cell resolution. This protocol details how to generate GEDI-expressing cancer cell lines, empirically determine stress-induced GEDI thresholds using radiation or chemotherapeutic agents, and perform time-resolved imaging and image analysis to track cell fate. This workflow is optimized for high-throughput drug and radiation screening in heterogeneous populations and is especially useful for identifying chemo- and radio-resistant subclones. Key limitations include the …

Antiestrogens As Bone Protective Therapeutics For Estrogen Receptor-Positive Breast Cancer In The Presence Of Osteoporosis, Faith E. Parker, Emily K. Zboril, David C. Boyd, Rachel Myrick, J. Chuck Harrell

UROP Posters

Breast cancer (BC) is one of the most significant causes of mortality among women and the second leading cause of cancer death in women. The estrogen receptor (ER) is a key oncogenic driver in the majority of breast cancer. ER+ BC is the most common molecular subtype of BC. Management of ER+ breast cancer varies depending on menopausal status. For premenopausal women, the goal is to suppress estradiol production from the ovaries with surgical oophorectomy and/or aromatase inhibitors. In postmenopausal women, endocrine therapy (ET) serves to suppress estradiol production from sources other than the ovaries. During the menopausal transition, estradiol …

A Phosphorylation Study Of Serine-8 And 26 In Two Fragments Of Amyloid Beta, A Peptide Involved In Alzheimer's Disease And Cancer, Colby J. Merrill

Senior Honors Theses and Projects

Both cancer and Alzheimer’s disease (AD) affect many people in the United States and impact the families of patients suffering from these challenging illnesses. Recently, it has been reported that these two diseases share several key pathophysiological features, and an inverse relationship exists between them. These diseases share several biochemical modulators, most notably the amyloid-beta protein, which affects tissues in both AD and cancer by misfolding and aggregating. Phosphorylation is believed to regulate the aggregation and toxicity of amyloid-beta by altering the protein's shape and charge, thereby changing its interactions with cells. Phosphorylation can also toggle some proteins on and …

Fluorescent Protein Imaging Approaches Uncover Dynamic Subcellular Distribution Of Core Clock Proteins In Neurospora Crassa, Ziyan Wang

Dartmouth College Ph.D Dissertations

Circadian clocks are endogenous self-sustained timekeeping systems that allow organisms to anticipate and adapt to daily environmental cycles. Found in diverse forms of life, these molecular clocks regulate the expression of ~ 40% of the genome in animals, fungi, and plants. In animals and fungi, circadian oscillators are built on transcription-translation feedback loops (TTFLs), in which positive regulators drive the expression of negative regulators which, once synthesized and imported into the nucleus, inhibit their own activators. This precisely regulated negative feedback incorporates multiple steps of delays that are essential for generating ~24-hour rhythms. Through these mechanisms, circadian clocks temporally coordinate …

Advancing Lipidomics Through Fluoroalcohol-Induced Multiphase Fractionation And Orthogonal Lc×Lc–Ms Detection, Md Al Amin

Chemistry & Biochemistry Dissertations

Comprehensive characterization of the lipidome remains a significant analytical challenge due to the immense structural diversity, wide dynamic range, and complex physicochemical continuum of lipid species. Conventional extraction methods, such as those by Bligh–Dyer and Folch, and one-dimensional liquid chromatography (1D-LC) often fail to resolve this complexity, leading to chromatographic overlap, severe ion suppression, and limited coverage of low-abundance or highly hydrophobic species. This dissertation addresses these bottlenecks by establishing a separation-driven analytical framework that integrates novel fluoroalcohol-induced multiphase systems (FAiTPS) with orthogonal multidimensional liquid chromatography–mass spectrometry (LC×LC–MS).

The core of this research is the development and physicochemical characterization of …