Biochemistry Commons^™

Molecular Mechanisms Regulating Prometaphase And Metaphase States For Faithful Chromosome Segregation, Sarah Yvette Valles

Dartmouth College Ph.D Dissertations

Cells progress through different stages of the cell cycle as they ultimately prepare to divide during mitosis. Mitosis relies on many interconnected networks to carry out the coordinated events required for faithful chromosome segregation. When a cell enters mitosis, chromosomes are highly condensed and sister chromatids are held together by cohesion. Kinetochores assemble at the constricted regions on each chromosome. The kinetochore is a large macromolecular structure composed of many proteins that form the binding site for microtubules of the mitotic spindle to attach. These kinetochore-microtubule (k-MT) attachments serve to align chromosomes at the center of the cell and are …

Protocol For Optimizing Production And Quality Control Of Infective Ecohiv Virions, Hammodah Rawhi Hammodah Alfar, Daphne N. Pariser, Harry Chanzu, Smita Joshi, Daniёlle M. Coenen, Joshua Lykins, Kanakanagavalli Shravani Prakhya, Mary Jane Potash, Wei Chao, Jennifer Kelschenbach, David J. Volsky, Kelly Metcalf-Pate

Saha Cardiovascular Research Center Faculty Publications

EcoHIV is a model of HIV infection that recapitulates aspects of HIV-1 pathology in mice. However, there are limited published protocols to guide EcoHIV virion production. Here, we present a protocol for producing infective EcoHIV virions and essential quality controls. We describe steps for viral purification, titering, and multiple techniques to analyze infection efficacy. This protocol produces high infectivity in C57BL/6 mice which will aid investigators in generating preclinical data.

Characterization Of Pathological Tau Mutants, Charles J. Mcdonald

Dissertations, Theses, and Capstone Projects

Tau is a protein expressed exclusively in glia and neurons in the central nervous system and implicated in several neurogenerative diseases called “tauopathies”. Among all the tauopathies, one third is characterized by the presence of genetic mutations leading to the synthesis of tau proteins with single amino acid substitutions at specific locations and affecting protein function. While most of the initial studies have emphasize the functional role of tau as modulator of the axonal cytoskeleton, it has recently been well accepted that tau is also an intrinsically disordered protein that tends to form membraneless organelles called coacervates, due to a …

Characterization And Modulation Of The Emergent Material Properties Of Biomolecular Condensates, Alfredo Vidal Ceballos

Dissertations, Theses, and Capstone Projects

The discovery of membraneless organelles has revolutionized the field of cell biology and our understanding of cell compartmentalization. These organelles lack a distinct phospholipid bilayer and interact with the cytoplasm mediated by a liquid-liquid interface. The emergent properties and characterization of these organelles are essential for decoding the mechanisms underlying their function and dysfunction. In this thesis, we focus on two reconstituted in-vitro model systems of protein condensates and advance current methodology in order to address these fundamental questions. The first model system examined is the neuronal granule protein Fragile X Mental Retardation Protein (FMRP), an RNA-binding protein, that aids …

Magnetically-Driven Therapeutic Agents Delivery System Using Iron Oxide Nanocages And Enhancement Of Exosome Secretion, A Potential Biological Drug Delivery Carrier, Min A Kang

Dissertations, Theses, and Capstone Projects

Nano-scale particles have attracted research attention due to their differences in properties such as penetration, circulation, and toxicity compared to bulk materials. This thesis mainly focused on using 20 nm iron oxide nanoparticles as siRNA delivery carriers under the alternating magnetic field and the development of a method to amplify the secretion of 150 nm exosomes from the cells, which could potentially use as a biological drug carrier.

Chapter 2 discusses a magnetically driven nanoparticle therapeutic agent delivery system, which efficiently modified the gene expression post-transcriptionally. In this work, we examined whether the caged-shaped 20nm iron oxide nanoparticles (IO-nanocages) can …

Construction And Performance Optimization Of Bioconjugated Nanosensors For Early Detection Of Breast Cancer And Pro-Inflammatory Diseases, Pooja Gaikwad

Dissertations, Theses, and Capstone Projects

In recent years, nanosensors have emerged as a tool with strong potential in medical diagnostics. Single-walled carbon nanotube (SWCNT) based optical nanosensors have notably garnered interest due to the unique characteristics of their near-infrared fluorescence emission, including tissue transparency, photostability, and various chiralities with discrete absorption and fluorescence emission bands. Additionally, the optoelectronic properties of SWCNT are sensitive to the surrounding environment, which makes them suitable for in vitro and in vivo biosensing. Single-stranded (ss) DNA-wrapped SWCNTs have been reported as optical nanosensors for cancers and metabolic diseases. Breast cancer and cardiovascular diseases are the most common causes of death …

Characterization Of The Conformational Binding Of N-Methyl Mesoporphyrin Ix With Dna Model Telomeric G-Quadruplex Forming Sequences, Jessica Desamero

Dissertations, Theses, and Capstone Projects

DNA G-quadruplexes are alternative secondary structures formed from guanine rich DNA sequences. G-quadruplexes are found most abundantly at the ends of chromosomes called telomeres, where they can ultimately prevent further tumor growth and progression. Thus, quadruplex interactive agents, or ligands that can bind to and stabilize DNA G-quadruplex structures, are of high interest for their potential chemotherapeutic abilities. One quadruplex interactive agent is the porphyrin N-methyl mesoporphyrin IX (NMM), which has high binding selectivity for quadruplex structures. While the NMM-quadruplex complex in crystallized form has been greatly studied, this complex in solution form is not as well studied. Through circular …

Bacteroides Fragilis In The Gut Microbiomes Of Alzheimer’S Disease Activates Microglia And Triggers Pathogenesis In Neuronal C/Ebpβ Transgenic Mice, Yiyuan Xia, Yifan Xiao, Zi-Hao Wang, Ashfaqul M. Alam, John P. Haran, Beth A. Mccormick, Xiji Shu, Xiaochuan Wang, Keqiang Ye

Markey Cancer Center Faculty Publications

Gut dysbiosis contributes to Alzheimer’s disease (AD) pathogenesis, and Bacteroides strains are selectively elevated in AD gut microbiota. However, it remains unknown which Bacteroides species and how their metabolites trigger AD pathologies. Here we show that Bacteroides fragilis and their metabolites 12-hydroxy-heptadecatrienoic acid (12-HHTrE) and Prostaglandin E2 (PGE2) activate microglia and induce AD pathogenesis in neuronal C/EBPβ transgenic mice. Recolonization of antibiotics cocktail-pretreated Thy1-C/EBPβ transgenic mice with AD patient fecal samples elicits AD pathologies, associated with C/EBPβ/Asparaginyl endopeptidase (AEP) pathway upregulation, microglia activation, and cognitive disorders compared to mice receiving healthy donors’ fecal microbiota transplantation (FMT). Microbial 16S rRNA sequencing …

Unleashing The Potential Of 1,3-Diketone Analogues As Selective Lh2 Inhibitors, Juhoon Lee, Hou-Fu Guo, Shike Wang, Yazdan Maghsoud, Erik Antonio Vázquez-Montelongo, Zhifeng Jing, Rae M. Sammons, Eun Jeong Cho, Pengyu Ren, G. Andrés Cisneros, Jonathan M. Kurie, Kevin N. Dalby

Markey Cancer Center Faculty Publications

Lysyl hydroxylase 2 (LH2) catalyzes the formation of highly stable hydroxylysine aldehyde-derived collagen cross-links (HLCCs), thus promoting lung cancer metastasis through its capacity to modulate specific types of collagen cross-links within the tumor stroma. Using 1 and 2 from our previous high-throughput screening (HTS) as lead probes, we prepared a series of 1,3-diketone analogues, 1−18, and identified 12 and 13 that inhibit LH2 with IC50’s of approximately 300 and 500 nM, respectively. Compounds 12 and 13 demonstrate selectivity for LH2 over LH1 and LH3. Quantum mechanics/molecular mechanics (QM/MM) modeling indicates that the selectivity of 12 and 13 may stem from …

Changes In The Epigenetic Landscape Of Oligodendrocyte Progenitor Cells With Time, David K. Dansu

Dissertations, Theses, and Capstone Projects

Most neonatal oligodendrocyte progenitors (nOPCs) give rise to myelinating oligodendrocytes during development, while a proportion are retained as proliferative undifferentiated cells in the adult brain (aOPCs). Previous studies have reported distinct properties for those two populations but the molecular mechanisms underlying these intrinsic differences are not well understood. Using RNA-sequencing and unbiased histone proteomics analysis, we identify transcripts and histone marks that are higher in aOPCs than nOPCs. The genome-wide ChIP-sequencing analysis of chromatin from aOPCs compared to nOPCs detects greater occupancy of the H4K8ac mark at loci corresponding to the higher transcript levels of oligodendrocyte-specific transcription factors and lipid …

Nanodiscs: A Novel Approach To The Study Of The Methionine Abc Transporter System, Michael T. Winslow

Master's Theses

Membrane transporter proteins play the vital role of moving compounds in and out of the cell and are essential for all living organisms. ATP Binding Cassette (ABC) family transporters function both as importers and exporters in prokaryotes. MetNI is an E. coli Type I ABC transporter responsible for the uptake of methionine into the cytosol from the cell periplasmic space through the cell membrane to maintain intracellular methionine pools. ABC transporters, like other membrane proteins, are most often mechanistically and structurally studied in vitro, solubilized by detergents. However, detergent micelles may affect the conformational changes of membrane proteins relative to …

Relationship Between Plasma Fluoride Levels, Glutathione Peroxidase Activity, Hemoglobin, And Abortion In Rural And Urban Pregnant Women From Settat (Morocco), Lalla Asmaa Katir Masnaoui, Abdellatif Rahim, Habiba Bouchab, Bouchra El Amiri, Boubker Nasser, Essamadi Abdel Khalid

Makara Journal of Health Research

Background: This study aimed to investigate the relationship between plasma fluoride and hemoglobin levels, glutathione peroxidase (GPx) activity, and abortion among rural and urban pregnant women from Settat province (Morocco).

Methods: Blood samples were collected from rural pregnant women who had not undergone abortion (N = 224), rural pregnant women who had an abortion (N = 38), urban pregnant women who had not undergone abortion (N = 163), and urban pregnant women who had an abortion (N = 14).

Results: The highest (p < 0.01) plasma fluoride levels and the lowest (p < 0.01) GPx activity were observed in rural pregnant women. In all participants, plasma fluoride levels were significantly higher (p < 0.001), and the GPx activity was significantly (p < 0.001) lower in pregnant women who had an abortion compared with those who did not undergo such process. No significant difference was observed between the hemoglobin levels of all participants. Furthermore, abortion was positively correlated with plasma fluoride levels (p < 0.001) and negatively correlated with GPx activity (p < 0.001) in rural participants.

Conclusions: Rural pregnant women had higher plasma …

Utilizing Low-Cost Sensors To Monitor Indoor Air Quality In Mongolian Gers, Callum Flowerday, Jaron C. Hansen, Phil Lundrigan, Christopher Kitras

Faculty Publications

Air quality has important climate and health effects. There is a need, therefore, to monitor air quality both indoors and outdoors. Methods of measuring air quality should be cost-effective if they are to be used widely, and one such method is low-cost sensors (LCS). This study reports on the use of LCSs in Ulaanbataar, Mongolia to measure PM_2.5 concentrations inside yurts or “gers”. Some of these gers were part of a non-government agency (NGO) initiative to improve insulating properties of these housing structures. The goal of the NGO was to decrease particulate emissions inside the gers; a secondary result …

Identification Of A Small Regulatory Rna Usps Associated With The Universal Stress Protein In Lactobacillus Species, Zarah M. Fowler, Sasha S. Bronovitskiy, Finn K. Rose, Brian M. Lee

Journal of the South Carolina Academy of Science

The gut microbiome is a complex habitat with many bacterial species, each playing crucial roles in regulating various physiological processes in the body. As the use of probiotics to combat human disease continues to increase, it is important to understand the mechanisms by which probiotic bacteria regulate their interactions with other bacteria and their host. Our exploration of the physiological functions of probiotic bacteria hopes to elucidate the role of small regulatory RNA (sRNA) in regulating gene expression within the microbiome. The goal of this project was to characterize the structure and function of the sRNA, UspS, which is found …

Broadband Cavity-Enhanced Absorption Spectroscopy (Bbceas) Coupled With An Interferometer For On-Band And Off-Band Detection Of Glyoxal, Callum Flowerday, Jaron Hansen, Ryan Thalman

ScholarsArchive Data

These data are the raw data from the BBCEAS. The "data_" files are the PMT data and the "DualDetection_08_02_2023" files are the spectrograph data. The PMT data are found in column 7 of the sheet. Column 1 is the time stamp.

Morphometric Analysis And Biochemical Estimation Of Wild Shrimps (Family: Penaeidae) Found In Coastal Waters Of Pakistan, Noor Us Saher, Syeda Hadiqa Noor

Journal of Bioresource Management

The world recognition of Seafood nutritional value for human consumption remain consistent throughout the time. Different informations and aspects have been studied and considered and generated various data sets but limited informations found about the biochemical concentration of various fishery species caught in the Pakistan. Therefore, the recent study design to evaluate the proximate levels of components in the edible component (flesh) of commercial shrimp species were studied. Four shrimp species; Fenneropenaeus indicus, Metapenaeopsis stridulans, Metapenaeus stebbingi, and Parapenaeopsis stylifera were selected for the assessment of proximate composition. The selected shrimp species were collected from the fishery catch of Korangi …

Rural Science Teachers Social Network Analysis Matrices, Rebecca L. Sansom, Tracy Poulsen

ScholarsArchive Data

These are the social network matrices for our study of rural science teachers. Each matrix is located on a separate tab on the spreadsheet.

Effect Of Tamoxifen On Proteome Expression During In Vitro Myogenesis In Murine Skeletal Muscle C2C12 Cells, Emily A. Morris, Ahlenne Abreu, S. P. Scordilis

Biological Sciences: Faculty Publications

Tamoxifen (TMX), a selective estrogen receptor modulator, is commonly used in the treatment of hormone-responsive cancers. However, the effects of TMX in anabolic tissues harboring estrogen receptors, such as skeletal muscle, are poorly understood. We report a tandem mass-tag approach to TMX-treated myogenesis in C₂C₁₂ cells, a well-characterized model of in vitro murine skeletal muscle differentiation. A longitudinal analysis of >10,000 proteins identified in untreated C₂C₁₂ myogenesis revealed a novel subset of 1,062 myogenically regulated proteins. These proteins clustered into five distinct longitudinal expression trends which significantly overlap those obtained in similar analyses performed …

Identification And Characterization Of Silk Gland Specific Ugt34 Gene In Helicoverpa Zea, Courtney Nicole Wynn

Theses and Dissertations

Uridine diphosphate glycosyltransferase (UGT) is a multigene family of enzymes responsible for catalyzing glycosylation of small hydrophobic molecules. Recently, a genomic analysis of the corn earworm (Helicoverpa zea) identified 45 different UGT genes. We discovered a UGT gene (UGT34) showing high levels of expression exclusively in the silk gland tissue. The expression levels of UGT34 were analyzed in different developmental stages and silk gland sub-segments, revealing that UGT34 is generally expressed at all larval instar stages and largely expressed in the middle and posterior subsegments of the silk glands. The soybean looper (Chrysodeixis includens), another noctuid …

Upland Cotton And Nematodes: An Analysis Of Historical Resistance, Upcoming Threats, And Co-Inoculation Effects, Amanda Gaudin

Theses and Dissertations

Upland cotton (Gossypium hirsutum ) is an important fiber crop grown throughout the southern United States. Plant-pathogenic nematodes are worm-like animals that feed on the roots of most agronomic crops, including cotton. The southern root-knot nematode (Meloidogyne incognita, RKN) and the reniform nematode (Rotylenchulus reniformis, RN) cause significant yield losses in cotton every year. Current sources of resistance are effective but limited, therefore historical screenings of cotton accessions were revisited in search for novel resistance sources. None were identified but many of the screened accessions possessed markers of known root-knot nematode and reniform nematode resistance. …

Spatial Structure Formation By The Post-Transcriptional Gene Regulator Rsme In Pseudomonas Fluorescens Pf0-1, Anton Evans

Electronic Theses and Dissertations

Microorganisms are often found in microbial communities we call biofilms. Organisms living in these crowded environments have significant evolutionary pressure to retain access to the resources necessary to sustain life. My research uses the bacterium Pseudomonas fluorescens Pf0-1 to study how organisms evolve strategies to solve this crowding problem as aging colonies repeatedly generate mutant patches. These mutants expand the reach of the colony resulting in decreased local density as they push themselves up to the resource rich surface. These spatial structures result from social interactions between the mutant and the parental cells mediated through extracellular secretions, resulting in the …

Mechanisms Behind The Chaperone Activity Of Nucleic Acids, Theodore J. Litberg

Electronic Theses and Dissertations

Understanding the interplay between nucleic acids and protein aggregation is integral to the understanding of proteostasis, aging, and neurodegenerative disease progression. Nucleic acids are known to modulate the aggregation of PrP, tau, ⍺-synuclein, and other disease relevant proteins. Although the interactions between misfolded protein and nucleic acids can play a role in disease, this interaction may potentially be beneficial as well. Our group and others have shown nucleic acids can be powerful chaperones. Previous work has shown both RNA and DNA can prevent protein aggregation and RNA can pass off protein clients to the heat shock protein (Hsp) system. Here …

Reactive Oxygen Species And Weak Magnetic Fields: Unraveling The Mechanisms Of Planarian Regeneration And Tissue Growth, Luke James Kinsey

Dissertations

Reactive oxygen species (ROS) play a critical role in basic cellular behaviors such as apoptosis, proliferation, and differentiation. These molecules once thought to be harmful byproducts of metabolism, are also required for many complex and ubiquitous processes like wound healing, development, and regeneration. This study investigates the influence of ROS on planarian regeneration, with a particular focus on ROS dynamics in stem cell-mediated tissue growth. Data reveal that modulation of ROS levels leads to changes in cellular behaviors and tissue growth outcomes. Inhibition of ROS accumulation blocks stem cell proliferation and tissue growth, preventing planarian regeneration, while partial ROS accumulation …

Investigating The Effects Of E219 Mutations In M. Tuberculosis Indole-3-Glycerol Phosphate Synthase, Cinthya Moran

Theses, Dissertations and Culminating Projects

Tuberculosis (TB) is a serious infectious disease caused by Mycobacterium tuberculosis. Tuberculosis drug resistance is increasingly a problem, but recent research has provided results that suggest Indole-3-Glycerol Phosphate Synthase (IGPS) could be a potential drug target. IGPS is an enzyme that catalyzes the fourth step in the tryptophan biosynthesis pathway, a crucial process for optimal Mycobacterium tuberculosis growth. In this research, we studied IGPS from Mycobacterium tuberculosis (MtIGPS) to shed light on a particular conserved residue that has not been studied in depth in any IGPS homolog. My investigation focuses on understanding the role of the active site residue E219. …

Phenotypic And Transcriptomic Characterization Of Rice Snrk1 Mutants Developed By Crispr/Cas9 Mutagenesis, Maria Clara Faria Chaves

Graduate Theses and Dissertations

SnRK1 is a heterotrimeric protein kinase that is composed of a catalytic subunit (α) and two regulatory subunits (β and βγ), and it has a main role in regulating energy homeostasis in the plant by modulating anabolic and catabolic process. SnRK1 phosphorylates and alters the activities of enzymes involved in metabolism and regulates gene expression by altering the activity of chromatin-remodeling enzymes or the transcription factors. Rice contains three functional paralogs of SnRK1α: SnRK1αa (LOC_Os03g17980), SnRK1αb (LOC_Os08g37800), and SnRK1αc (LOC_Os05g45420). This study focused on the function of these SnRK1 paralogs by evaluating the phenotypic and transcriptomic characteristics and the disease …

Epitranscriptomic Regulation In Breast Cancer And Pcb-Induced Liver Disease., Belinda Petri

Electronic Theses and Dissertations

Post-transcriptional RNA modifications including N6-methyladenosine (m6A) regulate mRNA stability, splicing, and translation. My research examined m6A in two disease models: breast cancer (BCa) and non-alcoholic fatty liver disease (NAFLD). Acquired resistance to endocrine therapies (ET) develops in approximately 20% of BCa patients with estrogen receptor α positive (ER+) tumors following treatment. The mechanisms by which tumor cells evade ET are not completely understood. Using a cell line model, we investigated the role of an m6A reader protein, HNRNPA2B1 (A2B1) that is upregulated in ET-resistant ER+ BCa cells. Stable overexpression of A2B1 in ET-sensitive MCF-7 cells (MCF-7-A2B1), results in ET resistance, …

Determining The Existence And Regulation Of Microlipophagy In Primary Brown And White Adipocytes, Sara C. Arenas De Leon

Biomedical Sciences ETDs

Lipids are one of life’s four main macromolecules and provide essential functions to cells.

The degradation of lipid droplets and mobilization of lipids occurs through lipolysis. Emerging evidence demonstrates evidence of a selective form of autophagy in lipolysis. The process of microlipophagy has only recently been described, and many features of its regulation are still poorly understood. Our recent study showed that inhibiting mammalian target of rapamycin complex 1 (mTORC1) pathway by depletion of Raptor in adipocytes led to an influx of lysosomes and accumulation of lipid droplets within lysosome. Here, we expand on these previous findings. We were able …

X-Ray Crystal Structure Of E399q,E708q Ecm16 Double Mutant, Gileydis Guillama

Open Access Theses & Dissertations

The use of antibiotics has undoubtedly been a boon for humanity in combating infections and microbial threats. However, their widespread utilization has contributed to the emergence and spread of antibiotic resistance, which now poses a significant public health challenge. Streptomyces bacterium, produce diverse secondary metabolites with antibacterial, antifungal, antiviral, antitumoral, and immunosuppressant activities. Among these compounds is echinomycin, a nonribosomal peptide antibiotic synthesized by Streptomyces lasalocidi, which inhibits DNA replication and transcription by intercalating the DNA duplex at CpG steps. A gene called ecm16 was identified in the echinomycin biosynthetic gene cluster, which provides echinomycin self-resistance. Ecm16 recognizes DNA duplexes …

Structural Study Of Lsd13 And Lsd14 Type I Modular Polyketide Synthases From The Lasalocid A Biosynthesis Pathway, Dayan Viera

Open Access Theses & Dissertations

Bioactive natural products often possess a complex structure and have a large size which make their chemical synthesis highly challenging. To overcome this challenge, we are developing a biosynthetic method for production of natural products and their analogs. This technology is expected to decrease the synthesis time from years to weeks and reduce the cost of drug production by multiple orders of magnitude. We are investigating the biosynthesis pathway of lasalocid A, an anticancer antibiotic, to develop this technology. Specifically, we aim to characterize the enzymes structurally and biochemically in this pathway, thus paving the way for their rational engineering. …

Co-Targeting Nucleus Accumbens Associate 1 And Nf-Κb Signaling Synergistically Inhibits Melanoma Growth, Lixiang Gu, Xingcong Ren, Chrispus Ngule, Xiaofang Xiong, Jianxun Song, Zhiguo Li, Jin-Ming Yang

Markey Cancer Center Faculty Publications

Nucleus-accumbens-associated protein-1 (NAC1) is a cancer-related transcriptional factor encoded by the NACC1 gene, which is amplified and overexpressed in various human cancers and has been appreciated as one of the top potential cancer driver genes. NAC1 has therefore been explored as a potential therapeutic target for managing malignant tumors. Here, we show that NAC1 is a negative regulator of NF-κB signaling, and NAC1 depletion enhances the level of the nuclear NF-κB in human melanoma. Furthermore, the inhibition of NF-κB signaling significantly potentiates the antineoplastic activity of the NAC1 inhibition in both the cultured melanoma cells and xenograft tumors. This study …