Biochemistry, Biophysics, and Structural Biology Commons^™

Structural Insights Into The Cl-Par-4 Protein: Ionic Requirements, Conformational Transitions, And Interaction With Cisplatin, Krishna Kumar Raut

Chemistry & Biochemistry Theses & Dissertations

Cancer continues to be the leading global cause of death, with challenges in early diagnosis, drug resistance, non-specific drug targeting, and cancer recurrence and metastasis posing formidable obstacles in cancer therapy. In this context, Prostate Apoptosis Response-4 (Par-4), a pro-apoptotic tumor suppressor protein, emerged as a promising therapeutic target due to its ability to selectively induce apoptosis in cancer cells, thereby minimizing the drug-associated adverse effects. However, a comprehensive understanding of the structural features of Par-4, specifically the caspase-cleaved fragment (cl-Par-4), is crucial for therapeutic advancements.

This dissertation investigated the effects of various ions, both monovalent and divalent, on the …

Metals And Metal Complexes In Diseases With A Focus On Covid-19: Facts And Opinions, Agnieszka Ścibior, Manuel Aureliano, Alvin A. Holder, Juan Llopis

Chemistry & Biochemistry Faculty Publications

In the present Special Issue on “Metals and Metal Complexes in Diseases with a Focus on COVID-19: Facts and Opinions”, an attempt has been made to include reports updating our knowledge of elements considered to be potential candidates for therapeutic applications and certain metal-containing species, which are extensively being examined towards their potential biomedical use due to their specific physicochemical properties. The Special Issue compiles data on the role of metals in COVID-19 and focuses on other illnesses and biological processes that affect metal metabolism. It consists of eight manuscripts, including five review articles and three original research papers (Figure …

Synthesis, Characterization, And Cytotoxicity Studies Of A Copper(Ii) Complex With Vanillin 3-Ethyl-Thiosemcarbazone A Ligand, Novia Mann, Ifeoluwa Oyeyemi, Duaa R. Alajroush, Elizabeth A. Tonsel-White, Stephen J. Beebe, Alvin Holder

Undergraduate Research Symposium

Triple-negative breast cancer (TNBC) is one of the most aggressive and challenging breast cancer subtypes to treat, as these cancer cells lack three common receptors: estrogen, progesterone, and human epidermal growth factor receptor 2. The multiple oxidation states transition metals can occupy have made this narrowly explored group popular for anti-cancer research in recent decades. Furthermore, the success of cisplatin, which has platinum as a metal center, while being a cancer-fighting agent with serious side effects, has caused other metal centers to be investigated as possible alternatives as chemotherapeutic drugs. Copper, as a biologically essential metal, makes an attractive candidate …

Isotopic Evidence For Sources Of Dissolved Carbon And The Role Of Organic Matter Respiration In The Fraser River Basin, Canada, Britta M. Voss, Timothy I. Eglinton, Bernhard Peucker-Ehrenbrink, Valier Galy, Susan Q. Lang, Cameron Mcintyre, Robert G.M. Spencer, Ekaterina Bulygina, Zhaohui Aleck Wang, Katherine A. Guay

OES Faculty Publications

Sources of dissolved and particulate carbon to the Fraser River system vary significantly in space and time. Tributaries in the northern interior of the basin consistently deliver higher concentrations of dissolved organic carbon (DOC) to the main stem than other tributaries. Based on samples collected near the Fraser River mouth throughout 2013, the radiocarbon age of DOC exported from the Fraser River does not change significantly across seasons despite a spike in DOC concentration during the freshet, suggesting modulation of heterogeneous upstream chemical and isotopic signals during transit through the river basin. Dissolved inorganic carbon (DIC) concentrations are highest in …

Clostridioides Difficile Biofilm And Spore Production In Response To Antibiotics And Immune Stress, Adenrele M. Oludiran

Chemistry & Biochemistry Theses & Dissertations

The development of new therapeutic options against Clostridioides difficile (C. difficile) infection is a critical public health concern, as the causative bacterium is highly resistant to multiple classes of antibiotics. C. difficile, an anaerobic spore-forming Gram-positive pathogenic bacterium, is a major cause of hospital-acquired infections. C. difficile persists in the environment and spreads the infection to new hosts in the form of dormant spores and can persist within hosts as surface-attached biofilms. These studies investigate bacterial vegetative cell survival, biofilm formation, and sporulation in response to stress. Antimicrobial host-defense peptides (HDPs) are highly effective at simultaneously modulating …

Natural Phaeosphaeride A Derivatives Overcome Drug Resistance Of Tumor Cells And Modulate Signaling Pathways, Victoria Abzianidze, Natalia Moiseeva, Diana Suponina, Sofya Zakharenkova, Nadezhda Rogovskaya, Lidia Laletina, Alvin A. Holder, Denis Krivorotov, Alexander Bogachenkov, Alexander Garabadzhiu, Anton Ukolov, Vyacheslav Kosorukov

Chemistry & Biochemistry Faculty Publications

n the present study, natural phaeosphaeride A (PPA) derivatives are synthesized. Anti-tumor studies are carried out on the PC3, K562, HCT-116, THP-1, MCF-7, A549, NCI-H929, Jurkat, and RPMI8226 tumor cell lines, and on the human embryonic kidney (HEK293) cell line. All the compounds synthesized turned out to have better efficacy than PPA towards the tumor cell lines listed. Among them, three compounds exhibited an ability to overcome the drug resistance of tumor cells associated with the overexpression of the P-glycoprotein by modulating the work of this transporter. Luminex xMAP technology was used to assess the effect of five synthesized compounds …

Coastal Upwelling Enhances Abundance Of A Symbiotic Diazotroph (Ucyn-A) And Its Haptophyte Host In The Arctic Ocean, Corday R. Selden, Sveinn V. Einarsson, Kate E. Lowry, Katherine E. Crider, Robert S. Pickart, Peigen Lin, Carin J. Ashjian, P. Dreux Chappell

OES Faculty Publications

The apparently obligate symbiosis between the diazotroph Candidatus Atelocyanobacterium thalassa (UCYN-A) and its haptophyte host, Braarudosphaera bigelowii, has recently been found to fix dinitrogen (N²) in polar waters at rates (per cell) comparable to those observed in the tropical/subtropical oligotrophic ocean basins. This study presents the novel observation that this symbiosis increased in abundance during a wind-driven upwelling event along the Alaskan Beaufort shelfbreak. As upwelling relaxed, the relative abundance of B. bigelowii among eukaryotic phytoplankton increased most significantly in waters over the upper slope. As the host’s nitrogen demands are believed to be supplied primarily by UCYN-A, …

Microbial Labilization And Diversification Of Pyrogenic Dissolved Organic Matter, Aleksandar I. Goranov, Andrew S. Wozniak, Kyle W. Bostick, Andrew R. Zimmerman, Siddhartha Mitra, Patrick G. Hatcher

Chemistry & Biochemistry Faculty Publications

With the increased occurrence of wildfires around the world, interest in the chemistry of pyrogenic organic matter (pyOM) and its fate in the environment has increased. Upon leaching from soils by rain events, significant amounts of dissolved pyOM (pyDOM) enter the aquatic environment and interact with microbial communities that are essential for cycling organic matter within the different biogeochemical cycles. To evaluate the biodegradability of pyDOM, aqueous extracts of laboratory-produced biochars were incubated with soil microbes, and the molecular changes to the composition of pyDOM were probed using ultrahigh-resolution mass spectrometry (Fourier transform–ion cyclotron resonance–mass spectrometry). Given that solar irradiation …

Genetically Engineered Thermosynechococcus Elongatus Bp1: Assessment Of Potential Biorisks And Biofuel Production, Thu Ho Anh Nguyen-Jones

Chemistry & Biochemistry Theses & Dissertations

According to the International Energy Outlook 2019, released by the U.S. Energy Information Administration, it is projected that the energy consumption will increase up to 50% between 2018 and 2050 worldwide. As fossil fuel being a finite source of energy with the risk of depletion, many countries are now facing an energy security crisis. Therefore, it is important to develop other renewable and sustainable energy sources that will allow countries to shift away from depending on fossil fuels. Among several types of renewable energy, biofuel production using genetically engineered cyanobacteria is capturing much interest due to its many advantages. Different …

Computational Analysis Of Type 3 Iodothyronine Deiodinase: Potential Inhibitors, Substrate Binding, And Dimer Structure, Eric Scott Marsan

Chemistry & Biochemistry Theses & Dissertations

Thyroid hormones (THs) in mammalian tissues are crucial for development and maintaining metabolic homeostasis. Iodothyronine deiodinases (Dios) remove iodines from THs by a selenocysteine (Sec) residue, which either activates or inactivates them. Halogen bonding (XB) has been proposed to describe the interaction between the Se and I atoms of the T4-Dio complex. Disruption of TH homeostasis by xenobiotics, such as polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) can cause deleterious effects on the endocrine system. Experimental studies have indicated that PBDEs and PCBs could disrupt TH homeostasis by inhibiting Dio through XB formation. However, no current quantitative study exists …

Improvement Of Biochar Through Ozonization And Biosafety Of Genetically Engineered Cyanobacteria, Oumar Sacko

Chemistry & Biochemistry Theses & Dissertations

Through the innovative technique of biochar post-production surface oxygenation by ozonization, we were able to improve certain properties of biochar. In project one, the incubation of an insoluble phosphate rock material (hydroxyapatite) with the wet ozonized pine 400 biochar and its filtrate resulted in a solubilization of 80 times more phosphate from hydroxyapatite (569.0 mg/L ± 6.4) compared to the pure water-hydroxyapatite control (7.2 mg/L ± 0.3). The ozonized biochar may provide a new possible way to unlock the phosphorus from insoluble phosphate mineral phases. The cation exchange capacity (CEC) is a key property of biochar when used as a …

Electrohydrodynamic Simulations Of Capsule Deformation Using A Dual Time-Stepping Lattice Boltzmann Scheme, Charles Leland Armstrong

Mathematics & Statistics Theses & Dissertations

Capsules are fluid-filled, elastic membranes that serve as a useful model for synthetic and biological membranes. One prominent application of capsules is their use in modeling the response of red blood cells to external forces. These models can be used to study the cell’s material properties and can also assist in the development of diagnostic equipment. In this work we develop a three dimensional model for numerical simulations of red blood cells under the combined influence of hydrodynamic and electrical forces. The red blood cell is modeled as a biconcave-shaped capsule suspended in an ambient fluid domain. Cell deformation occurs …

Influence Of Monovalent And Divalent Ions In The Conformational Change Of Caspase-Cleaved Par-4 (Cl-Par-4) Tumor Suppressor Protein, Krishna K. Raut, Komala Ponniah, Steven M. Pascal

College of Sciences Posters

Prostate apoptosis response-4 (Par-4) is a pro-apoptotic tumor suppressor protein. We have shown that this 38 kDa full-length Par-4 (Fl-Par-4) protein is predominantly intrinsically disordered in vitro. In vivo, Par-4 is cleaved by caspase-3 at Asp-131 to generate a 24 kDa functionally active cleaved Par-4 (cl-Par-4) fragment. The cl-Par-4 protein inhibits the NF-κB-mediated cell survival pathway and causes selective apoptosis in various tumor cells. Our laboratory is interested in how the disorder-order balance within Fl-Par-4 and cl-Par-4 may be related to the balance between cell survival and cell death. Currently, we are using biophysical techniques such as circular …

Biophysical Characterization Of The Par-4 Tumor Suppressor: Evidence Of Structure Outside The Coiled Coil Domain And Interactions With Platinum Chemotherapeutics, Andrea Megan Clark

Chemistry & Biochemistry Theses & Dissertations

Prostate apoptosis response-4 (Par-4) is an apoptosis-inducing tumor suppressor protein. Full-length Par-4 has previously been shown to be a predominantly intrinsically disordered protein (IDP) under neutral conditions, with significant regular secondary structure evident only within the C-terminal coiled coil domain. However, IDPs can gain ordered structure through the process of induced folding, which often occurs under non-neutral conditions. Previous work has shown that the Par-4 leucine zipper, which is a subset of the C-terminal coiled coil domain, is disordered under neutral conditions, but forms a dimeric coiled coil at acidic pH. Increase in ionic strength was also shown to increase …

Evaluating The Role Of The Stringent Response Mechanism In Clostridioides Difficile Survival And Pathogenesis, Astha Pokhrel

Chemistry & Biochemistry Theses & Dissertations

The human pathogen Clostridioides difficile is increasingly tolerant of multiple antibiotics and causes infections with a high rate of recurrence, creating an urgent need for new preventive and therapeutic strategies. The stringent response, a universal bacterial response to extracellular stresses, governs antibiotic survival and pathogenesis in diverse organisms but has not previously been characterized in C. difficile. This dissertation explores the ability of C. difficile to mount the stringent response. The bacteria encode a full-length, canonical bifunctional Rel/Spo Homolog or RSH enzyme. C. difficile RSH is incapable of utilizing GTP as a substrate but readily synthesizes putative 5’-pGpp-3’ alarmones. …

Computational And Experimental Investigation Into The Determinants Of Protein Structure, Folding, And Stability In The Β-Grasp Superfamily, John T. Bedford Ii

Chemistry & Biochemistry Theses & Dissertations

Elucidating the mechanisms of protein folding and unfolding is one of the greatest scientific challenges in basic science. The overarching goal is to predict three-dimensional structures from their amino acid sequences. Understanding the determinants of protein folding and stability can be facilitated through the study of evolutionarily related but diverse proteins. Insights can also be gained through the study of proteins from extremophiles that may more closely resemble the primordial proteins. In this doctoral research, three aims were accomplished to characterize the structure, folding and unfolding behavior within the β-grasp superfamily. We propose that the determinants of structure, stability, and …

Methylation Of The D2 Dopamine Receptor Affects Binding With The Human Regulatory Proteins Par-4 And Calmodulin, Alexander Bowitch, Ansuman Sahoo, Andrea M. Clark, Christiana Ntangka, Krishna K. Raut, Paul Gollnick, Michael C. Yu, Steven M. Pascal, Sarah E. Walker, Denise M. Ferkey

Chemistry & Biochemistry Faculty Publications

No abstract provided.

Adenosine Triphosphate (Atp) As A Metric Of Microbial Biomass In Aquatic Systems: New Simplified Protocols, Laboratory Validation, And A Reflection On Data From The Literature, Alexander B. Bochdansky, Alison N. Stouffer, Nyjaee N. Washington

OES Faculty Publications

The use of adenosine triphosphate (ATP) as a universal biomass indicator is built on the premise that ATP concentration tracks biomass rather than the physiological condition of cells. However, reportedly high variability in ATP in response to environmental conditions is the main reason the method has not found widespread application. To test possible sources of this variability, we used the diatom Thalassiosira weissflogii as a model and manipulated its growth rate through nutrient limitation and through exposure to three different temperatures (15°C, 20°C, and 25°C). We simplified the ATP protocol with hot‐water or chemical extraction methods, modified a commercially available …

Structual Analysis Of The Cl-Par-4 Tumor Suppressor As A Function Of Ionic Environment, Krishna K. Raut, Komala Ponniah, Steven M. Pascal

Chemistry & Biochemistry Faculty Publications

Prostate apoptosis response-4 (Par-4) is a proapoptotic tumor suppressor protein that has been linked to a large number of cancers. This 38 kilodalton (kDa) protein has been shown to be predominantly intrinsically disordered in vitro. In vivo, Par-4 is cleaved by caspase-3 at Asp-131 to generate the 25 kDa functionally active cleaved Par-4 protein (cl-Par-4) that inhibits NF-κB-mediated cell survival pathways and causes selective apoptosis in tumor cells. Here, we have employed circular dichroism (CD) spectroscopy and dynamic light scattering (DLS) to assess the effects of various monovalent and divalent salts upon the conformation of cl-Par-4 in vitro. We have …

Detrital Neodymium And (Radio)Carbon As Complementary Sedimentary Bedfellows? The Western Arctic Ocean As A Testbed, Melissa S. Schwab, Jörg D. Rickli, Robie W. Macdonald, H. Rodger Harvey, Negar Haghipour, Timothy I. Eglinton

OES Faculty Publications

Interactions between organic and detrital mineral phases strongly influence both the dispersal and accumulation of terrestrial organic carbon (OC) in continental margin sediments. Yet the complex interplay among biological, chemical, and physical processes limits our understanding of how organo-mineral interactions evolve during sediment transfer and burial. In particular, diverse OC sources and complex hydrodynamic processes hinder the assessment of how the partnership of organic matter and its mineral host evolves during supply and dispersal over continental margins. In this study, we integrate new and compiled sedimentological (grain size, surface area), organic (%OC, OC-δ¹³C, OC-F¹⁴C), and inorganic …

Scaling The Effects Of Ocean Acidification On Coral Growth And Coral-Coral Competition On Coral Community Recovery, Nicolas R. Evensen, Yves-Marie Bozec, Peter J. Edmunds, Peter J. Mumby

Biological Sciences Faculty Publications

Ocean acidification (OA) is negatively affecting calcification in a wide variety of marine organisms. These effects are acute for many tropical scleractinian corals under short-term experimental conditions, but it is unclear how these effects interact with ecological processes, such as competition for space, to impact coral communities over multiple years. This study sought to test the use of individual-based models (IBMs) as a tool to scale up the effects of OA recorded in short-term studies to community-scale impacts, combining data from field surveys and mesocosm experiments to parameterize an IBM of coral community recovery on the fore reef of Moorea, …

Marine Phytoplankton Functional Types Exhibit Diverse Responses To Thermal Change, S. I. Anderson, A. D. Barton, Sophie Clayton, S. Dutkiewicz, T. A. Rynearson

OES Faculty Publications

Marine phytoplankton generate half of global primary production, making them essential to ecosystem functioning and biogeochemical cycling. Though phytoplankton are phylogenetically diverse, studies rarely designate unique thermal traits to different taxa, resulting in coarse representations of phytoplankton thermal responses. Here we assessed phytoplankton functional responses to temperature using empirically derived thermal growth rates from four principal contributors to marine productivity: diatoms, dinoflagellates, cyanobacteria, and coccolithophores. Using modeled sea surface temperatures for 1950-1970 and 2080-2100, we explored potential alterations to each group's growth rates and geographical distribution under a future climate change scenario. Contrary to the commonly applied Eppley formulation, our …

Not Too Hot, Not Too Cold, But Moderately Variable: The Influence Of Environmental Variability On Coral Thermal Tolerance, Courtney Nicole Klepac

Biological Sciences Theses & Dissertations

Anthropogenic climate change is causing an increase in the frequency and severity of marine heat waves, resulting in declining health of coral reef ecosystems worldwide. Coral bleaching events – the breakdown in symbiosis between the coral host and their intracellular photosynthetic algae – are increasingly common in recent years and contribute to widespread losses in coral cover. However, bleaching and heat stress responses vary across spatial scales both within and among coral species. Coral populations native to highly variable environments can have greater bleaching resistance than corals from more stable habitats and corals transplanted into these variable reef sites can …

Protonic Capacitor: Elucidating The Biological Significance Of Mitochondrial Cristae Formation, James Weifu Lee

Chemistry & Biochemistry Faculty Publications

For decades, it was not entirely clear why mitochondria develop cristae? The work employing the transmembrane-electrostatic proton localization theory reported here has now provided a clear answer to this fundamental question. Surprisingly, the transmembrane-electrostatically localized proton concentration at a curved mitochondrial crista tip can be significantly higher than that at the relatively flat membrane plane regions where the proton-pumping respiratory supercomplexes are situated. The biological significance for mitochondrial cristae has now, for the first time, been elucidated at a protonic bioenergetics level: 1) The formation of cristae creates more mitochondrial inner membrane surface area and thus more protonic capacitance for …

Probing Nanoelectroporation And Resealing Of The Cell Membrane By The Entry Of Ca2+ And Ba2+ Ions, Wenfei Bo, Mantas Silkunas, Uma Mangalanathan, Vitalij Novickij, Maura Casciola, Iurii Semenov, Shu Xiao, Olga N. Pakhomova, Andrei G. Pakhomov

Bioelectrics Publications

The principal bioeffect of the nanosecond pulsed electric field (nsPEF) is a lasting cell membrane permeabilization, which is often attributed to the formation of nanometer-sized pores. Such pores may be too small for detection by the uptake of fluorescent dyes. We tested if Ca²⁺, Cd²⁺, Zn²⁺, and Ba²⁺ ions can be used as nanoporation markers. Time-lapse imaging was performed in CHO, BPAE, and HEK cells loaded with Fluo-4, Calbryte, or Fluo-8 dyes. Ca²⁺ and Ba²⁺ did not change fluorescence in intact cells, whereas their entry after nsPEF increased fluorescence within <1 ms. The threshold for one 300-ns pulse was at 1.5–2 kV/cm, much lower than >7 …

Size-Dependent Inhibitory Effects Of Antibiotic Nanocarriers On Filamentation Of E. Coli, Preeyaporn Songkiatisak, Feng Ding, Pavan Kumar Cherukuri, Xiao-Hong Nancy Xu

Chemistry & Biochemistry Faculty Publications

Multidrug membrane transporters exist in both prokaryotic and eukaryotic cells and cause multidrug resistance (MDR), which results in an urgent need for new and more effective therapeutic agents. In this study, we used three different sized antibiotic nanocarriers to study their mode of action and their size-dependent inhibitory effects against Escherichia coli (E. coli). Antibiotic nanocarriers (AgMUNH–Oflx NPs) with 8.6 × 10², 9.4 × 10³ and 6.5 × 10⁵ Oflx molecules per nanoparticle (NP) were prepared by functionalizing Ag NPs (2.4 ± 0.7, 13.0 ± 3.1 and 92.6 ± 4.4 nm) with a monolayer …

Npgreat: Hybrid Assembly Of Human Subtelomeres With The Use Of Nanopore And Linked-Read Datasets, Eleni Adam, Desh Ranjan, Harold Riethman

College of Sciences Posters

The telomeres are vitally important regions that are located at the tips of the chromosomes. Their dysfunction, caused by length shortening can lead to senescent cells, which in turn cause age-related diseases, including cancer. The subtelomeres, located next to the telomeres, possess the critical role of regulating the adjacent telomere lengths. Even after many years of research, human subtelomeres have proven to be very hard to assemble due to their morphology. In order to overcome these problems, the hybrid assembly method we develop utilizes two of the latest available types of data, which complement each other: Linked-Reads and ultralong Nanopore …

Cylindrical Similarity Measurement For Helices In Medium-Resolution Cryo-Electron Microscopy Density Maps, Salim Sazzed, Peter Scheible, Maytha Alshammari, Willy Wriggers, Jing He

College of Sciences Posters

Cryo-electron microscopy (cryo-EM) density maps at medium resolution (5-10 Å) reveal secondary structural features such as α-helices and β-sheets, but they lack the side chains details that would enable a direct structure determination. Among the more than 800 entries in the Electron Microscopy Data Bank (EMDB) of medium-resolution density maps that are associated with atomic models, a wide variety of similarities can be observed between maps and models. To validate such atomic models and to classify structural features, a local similarity criterion, the F1 score, is proposed and evaluated in this study. The F1 score is theoretically normalized to a …

A Halogen Bonding Perspective On Iodothyronine Deiodinase Activity, Eric S. Marsan, Craig A. Bayse

Chemistry & Biochemistry Faculty Publications

Iodothyronine deiodinases (Dios) are involved in the regioselective removal of iodine from thyroid hormones (THs). Deiodination is essential to maintain TH homeostasis, and disruption can have detrimental effects. Halogen bonding (XB) to the selenium of the selenocysteine (Sec) residue in the Dio active site has been proposed to contribute to the mechanism for iodine removal. Polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) are known disruptors of various pathways of the endocrine system. Experimental evidence shows PBDEs and their hydroxylated metabolites (OH-BDEs) can inhibit Dio, while data regarding PCB inhibition are limited. These xenobiotics could inhibit Dio activity by competitively …

Outlier Profiles Of Atomic Structures Derived From X-Ray Crystallography And From Cryo-Electron Microscopy, Lin Chen, Jing He, Angelo Facchiano

Computer Science Faculty Publications

Background: As more protein atomic structures are determined from cryo-electron microscopy (cryo-EM) density maps, validation of such structures is an important task. Methods: We applied a histogram-based outlier score (HBOS) to six sets of cryo-EM atomic structures and five sets of X-ray atomic structures, including one derived from X-ray data with better than 1.5 Å resolution. Cryo-EM data sets contain structures released by December 2016 and those released between 2017 and 2019, derived from resolution ranges 0–4 Å and 4–6 Å respectively. Results: The distribution of HBOS values in five sets of X-ray structures show that HBOS is sensitive distinguishing …