Biochemistry Commons^™

Mitochondrial Division: Synergizing In Mitochondrial Divisome, Ao Liu

Dartmouth College Ph.D Dissertations

Mitochondria are the energy factories of the cell. The dynamic nature of cells demands routine changes in mitochondrial morphology by fusion and division. The dynamin GTPase Drp1 is a central mitochondrial division protein, driving constriction of the outer mitochondrial membrane via oligomerization. At least four regulatory factors control Drp1 activity on the outer mitochondrial membrane (OMM): 1) receptor proteins (Mff, MiD49, MiD51, and Fis1); 2) actin filaments; 3) the mitochondrial phospholipid cardiolipin (CL); and 4) Drp1 post-translational modifications, of which two phosphorylation sites (S579 and S600) are the most well studied. However, the molecular mechanism of how these factors work …

Biogeography Of Special Metabolites Produced By Ant-Associated Bacteria, Katherine Hansen

Scripps Senior Theses

There is an urgent and growing need for novel antibiotics with the growing prevalence of antibiotic-resistant pathogens. Ecologically-guided discovery is a strategy that focuses on how and where specially evolved metabolites such as antibiotics are used in nature. This strategy reveals unique active molecules with potential for human use. An unexplored niche with great potential for antibiotic discovery exists with Southwestern fungus-farming Trachymyrmex ants and their Actinobacteria symbionts. In exchange for nutrients from the ant, the ants’ bacterial symbiont produces antifungal molecules that protect the ants’ fungal cultivar from invasion by pathogenic microorganisms. They also produce antibacterial molecules to protect …

Determination Of The Effects Of Added Methionine On The Toxicity Of Platinum Drugs In Saccharomyces Cerevisiae, Kassidy Owens, Jonathan White

Longwood Senior Thesis Proposal

Platinum (Pt) drugs are used in about half of all anticancer treatments. A common way to study Pt drugs is by using S. cerevisiae (brewer’s yeast) as a model cellular organism. One of the most commonly-used strains of yeast is BY4741, which is auxotrophic for (cannot synthesize) several small-molecule nutrients, including the amino acid methionine. Therefore, methionine must be supplemented in the cell culture medium. Interestingly, it is known that methionine can react with Pt compounds, including Pt drugs. Methionine-supplemented media continues to be used to study Pt drugs in yeast, especially BY4741, yet the potential for methionine to interfere …

Investigating Visinin-Like Protein 1 And Ubiquitinated Visinin-Like Protein 1 As Mild Traumatic Brain Injury Biomarkers, Yueming Wu

Theses and Dissertations--Chemistry

Traumatic brain injury (TBI) continues to be a significant cause of morbidity and mortality worldwide. Despite significant progress in understanding the complex pathophysiology of TBI, the underlying mechanisms remain poorly understood. The primary brain damage is acute and irreversible. However, secondary brain injuries often develop gradually over months to years, creating an opportunity for critical therapeutic interventions. In the past decade, research on TBI biomarkers has seen significant progress. This progress has been driven by the diverse nature of TBI pathologies and the challenges they present for evaluation, management, and prognosis. TBI biomarker proteins resulting from axonal, neuronal, or glial …

Extension Of The Ergot Alkaloid Gene Cluster, Samantha Joy Fabian

Graduate Theses, Dissertations, and Problem Reports (ETD)

Specialized metabolites produced by fungi impact human health. A large portion of the pharmaceuticals currently on the market are derived from metabolites biosynthesized by microbes. Ergot alkaloids are a class of fungal metabolites that are important in the interactions of environmental fungi with insects and mammals and also are used in the production of pharmaceuticals. In animals, ergot alkaloids can act as partial agonists or antagonists at receptors for 5-hydroxytryptamine (serotonin), dopamine, and noradrenaline as ergot alkaloids have chemical structures similar to those neurotransmitters. Therefore, they affect insects and mammals that consume them and can be used to produce drugs …

Identification And Functional Characterization Of Mads-Box Proteins And Ccos Involved In Carotenoid Metabolism In Durian Durio Zibethinus L. Pulps, Kittiya Tantisuwanichkul

Chulalongkorn University Theses and Dissertations (Chula ETD)

Durian (Durio zibethinus L.), known as the "King of fruits," holds significant economic importance in Thailand. Apart from its unique odor and sweet taste, durian pulp exhibits a yellow color, which is an important aspect of fruit quality. Carotenoids are essential compounds responsible for the yellow, orange, and red coloration in many fruits and vegetables. During durian fruit development and ripening processes, its pulp changes from white to yellow due to increased carotenoid accumulation. The carotenoid biosynthetic pathway, responsible for carotenoid production, is controlled by ethylene. However, the mechanism underlying this process in durian fruit is still unknow. Notably, the …

Producing Grnas For Use In Crispr-Cas9 Dna Editing Applications Via In Vivo T7 Rna Polymerase Transcription In Escherichia Coli., Christian A. Santiago

Honors Program Theses

The development of the CRISPR-Cas9 system is widely considered to be a breakthrough advancement in gene editing. Compared to traditional technologies, CRISPR is generally regarded as the most accessible, effective, and precise tool for inducing stable and inheritable gene edits in vivo. The CRISPR-Cas9 gene editing complex relies on the complementary binding of guide RNAs to specifically target a DNA sequence for endonuclease cleavage and mutagenesis. The production of gRNAs for use in CRISPR applications can become exceedingly complex and costly, as in vivo methodologies generally require the use of RNA polymerases that interfere with gRNA sequence identity and in …

Lead Induced Differences In Bone Properties In Osteocalcin +/+ And −/− Female Mice, G. Yildirim, W. C. Budell, O. Berezovska, S. Yagerman, S. S. Maliath, P. Mastrokostas, S. Tommasini, T. L. Dowd

Publications and Research

Lead (Pb) toxicity is a major health problem and bone is the major reservoir. Lead is detrimental to bone, affects bone remodelingand is associated with elderly fractures. Osteocalcin (OC) affects bone remodeling, improves fracture resistance and decreases with age and in some diseases. The effect of lead in osteocalcin depleted bone is unknown and of interest. We compared bone mineral properties of control and Pb exposed (from 2 to 6 months) femora from female adult C57BL6 OC+/+ and OC−/− mice using Fourier Transform Infrared Imaging (FTIRI), Micro-computed tomography (uCT), bone biomechanical measurements and serum turnover markers (P1NP, CTX). Lead significantly …

Characterizing Cellular Injury And Inflammation With Aldob-/-Mouse Model Of Mafld, Andy Rashid

All Master's Theses

Metabolic-associated fatty liver disease (MAFLD) affects 1 in 3 people in the US and is a healthcare burden on the order of billions of dollars. MAFLD is characterized by pathological lipid accumulation in the liver, excess production of triglycerides and cholesterol, and export of LDL particles that raise serum lipid levels. These metabolic perturbations can lead to the development of liver fibrosis, chronic inflammation, and insulin resistance. Diagnosing MAFLD prior to fibrosis is crucial for successful intervention and prevention of advanced liver disease and other metabolic complications. Fructose-1Phospahte (F1P) accumulation from fructose overconsumption can drive hepatic lipogenesis and MAFLD progression. …

Under Ice Photosynthetic Primary Production And Dark Carbon Fixation In A Temperate Freshwater System, Vanessa Cubillos Tellez

Dissertations, Master's Theses and Master's Reports

Ice-covered lakes are vulnerable to environmental change, especially those in the Northern Hemisphere where ice cover is rapidly declining due to global warming. These changes can alter metabolic processes and disrupt carbon cycling driven by primary producers who form the base of the food chain and are key to sustaining ecosystem function. Photosynthetic primary production and dark carbon fixation under the ice in the Keweenaw Waterway, a temperate freshwater system that is ice-covered for ~3 months out of the year, were studied using a carbon isotopic labeling (14C-bicarbonate) technique. Water samples were collected weekly during ice cover and monthly during …

Development Of Novel Cellular Assay Model And Therapeutic Deep Eutectic Solvents To Optimize The Activity Of Anticancer Agents, Nizam Uddin

Electronic Theses and Dissertations

Multidrug resistance (MDR) is the major burden behind chemotherapeutic treatment failure. It is the principal mechanism by which cancer cells evade chemotherapeutic treatment. As a result, aggressive cancer cells survive and continue uncontrolled cell division. Multidrug resistance affects survival rate of almost all types of cancer patients and death toll rises at an alarming rate. There are seven different mechanisms for evolving MDR. The most common mechanism in efflux activity of overexpressed ABC transporters. MRP1 is a prominent ABC transporter that pumps out a wide variety of anticancer drugs from the cells and thereby reduces intracellular drug concentrations and develops …

Modulatory Effects Of Deacetylated Sialic Acids On Breast Cancer Resistance Protein-Mediated Multidrug Resistance And Receptor Tyrosine Kinase-Targeted Therapy, Isaac Tuffour

Electronic Theses and Dissertations

Multidrug resistance (MDR) remains a major challenge in cancer treatment, accounting for over 90% of chemotherapeutic failures. Cancers utilize sugar residues to engage in multidrug resistance. The underlying mechanism of action involving glycans, specifically the glycan sialic acid (Sia) and its various functional group alterations, has not been explored. ATP-binding cassette (ABC) transporter proteins, key proteins utilized by cancers to engage in MDR pathways, contain Sias in their extracellular domains. Modulating the expression of acetylated-Sias on Breast Cancer Resistance Protein (BCRP), a significant ABC transporter implicated in MDR, in lung and colon cancer cells directly impacted the ability of cancer …

Specialized Metabolism In Retina, Retinal Pigmented Epithelium, And Testis, Siyan Zhu

Graduate Theses, Dissertations, and Problem Reports (ETD)

The retina and its neighboring retinal pigmented epithelium (RPE) are high energy-demanding and metabolically active tissues with specialized and complementary metabolism. They are metabolically interdependent and impact each other’s viability. Interestingly, many of the metabolic features in the retina and RPE are shared with the testis. For example, testis is also energy costly due to continuous sperm differentiation and it has similar metabolic inter-dependence between different testis cells. Both the retina and testis are vulnerable to mitochondrial metabolic impairments.

We conducted three research projects to understand 1) the nutrient utilization and communication in retina and RPE; 2) The profiling of …

Mammalian Dihydropyrimidine Dehydrogenase: Employing Transient State Kinetic Methods To Determine Catalytic And Inhibitory Mechanisms, Dariush Forouzesh

Dissertations

Dihydropyrimidine dehydrogenase (DPD) catalyzes the two-electron reduction of pyrimidine bases uracil and thymine as the first step in pyrimidine catabolism. The enzyme achieves this simple chemistry using a complex cofactor set including two flavins and four Fe4S4 centers. The flavins, FAD and FMN, interact with respective NADPH and pyrimidine substrates and the iron-sulfur centers form an electron transfer wire that links the two active sites that are separated by 56 Å. DPD accepts the common antineoplastic agent 5-fluorouracil (5FU) as a substrate and so undermines the establishment of efficacious toxicity. Though studied for multiple decades, a precise description of the …

The Affect Of Dha Concentration On Lipid Membrane Fluidity, Elise Rezabeck

Williams Honors College, Honors Research Projects

My proposed project will be creating large unilaminar vesicles with varying concentrations of DHA in the vesicles. The diffusion in and out of these vesicles will be tracked by using singular lipid molecules. These singular lipid molecules will be tagged with fluorescence and viewed using an internal reflection fluorescence microscope. The data collected over the course of this project will then be analyzed using Matlab. The result of the project will be to find the specific lipid diffusion constant of these unilaminar vesicles. The relationship between the concentration of DHA and lipid diffusion and membrane fluidity will be found as …

Dual Mechanisms Contributing To Pyruvate Dehydrogenase Activity Deficiency In A Barth Syndrome Cell Model, Zhuqing Liang

Wayne State University Dissertations

Barth syndrome (BTHS) is a rare genetic disease that results from mutations in the TAFAZZIN gene, which encodes the cardiolipin (CL) remodeling enzyme tafazzin (Taz). The mechanisms linking perturbation of CL remodeling and the pathological features of BTHS are not understood. We have recently reported that intermediary metabolism is perturbed in BTHS, and activity of the metabolic gatekeeper enzyme pyruvate dehydrogenase (PDH) is deficient in BTHS models. The mechanism whereby PDH is regulated by Taz is unknown, and this knowledge gap represents an obstacle to the development of therapeutics to treat BTHS. Using an established C2C12 myoblast model of BTHS, …

Characterizing Vhh Domains As Stabilization And Oligomeric Control Modules, Niyati Patel

Graduate Research Theses & Dissertations

The biophysical properties of the VHH domain from heavy-chain-only antibodies obtained from the Camelidae family has expanded opportunities for novel antibody applications. The small, single domain nature of VHH domains makes them attractive modules for fusion proteins. Here, two VHH fusion systems were evaluated, RNase A-anti-RNase A VHH and GFPMut3aR80Q-anti-GFP VHH, to investigate how antigen-VHH fusions may enhance protein thermostability. The introduction of various length flexible linkers was hypothesized to play a role in stability, as well as influence the oligomeric state. Bovine Pancreatic Ribonuclease A, or RNase A, is an enzyme belonging to the ribonuclease A superfamily, which is …

Effects Of Nicotine Vs Non-Nicotine E-Cigarettes On The Aggression Behavior Of Crayfish, Alex Kimble

Williams Honors College, Honors Research Projects

This study looks at the effects of e-cigarette vapor with and without nicotine on the aggression behavior of crayfish (Procambarus clarkii). The treatment groups were control, nicotine, and non-nicotine. The mass, sex, and condition of their appendages were recorded before random assignment. For the purpose of this study only male crayfish were used as there were not enough female crayfish. The crayfish were then randomly assigned to each group and contained ten crayfish that were subjected to the e-cigarette vapor infused water environment for a twenty-four hour period. The control group did not contain e-cigarette vapor and was exposed to …

Effect Of An Oncogenic Her2 Mutant On Egfr Activity, Paige Kalik

Williams Honors College, Honors Research Projects

Studies have shown that HERs are involved in the progression of human cancers. Researchers have found that HER2 mutations in colorectal cancer are similar to mutations found in breast cancer. Recombinant antibodies are effective therapeutic treatments for cancers. Antibodies can also be used to determine how proteins function under normal and pathophysiological conditions while also identifying interacting partners. In this Honors Project, my aim is to investigate the effect of an oncogenic mutant of HER2. Considering the information above, the question researched in this project was: how does the S310F mutation affect the organization and function of HER2? The specific …

Characterization Of The Function And Regulation Of The Hmpv Phosphoprotein, Rachel Thompson

Theses and Dissertations--Molecular and Cellular Biochemistry

Human metapneumovirus (HMPV) is a non-segmented, negative strand RNA virus (NNSV) that frequently causes respiratory tract infections in infants, the elderly, and the immunocompromised. Despite the initial identification of HMPV in 2001, there are currently no FDA approved antivirals or vaccines available. Therefore, understanding the mechanism of HMPV replication is critical for the identification of novel therapeutic targets. A key feature in the replication cycle of HMPV and other NNSVs is the formation of membrane-less, liquid-like replication and transcription centers in the cytosol termed inclusion bodies (IBs). Recent work on NNSV IBs suggests they display characteristics of biomolecular condensates formed …

Investigating The Roles Of Platelet Bioenergetics In Hemostasis And Thrombosis, Kanakanagavalli Shravani Prakhya

Theses and Dissertations--Molecular and Cellular Biochemistry

Platelets use a series of energy-dependent processes to mediate hemostasis, yet it is unclear which metabolic fuels/pathways are critical for platelet function. Platelets are metabolically flexible, switching between glycolysis and oxidative phosphorylation (OxPhos) depending on oxygen tension and substrate availability. The deletion of GLUT1 and GLUT3 together revealed an essential role in platelet function and hemostasis. To study platelet bioenergetics, we used clot contraction. We created a sensitive and inexpensive method to simultaneously assess clot contraction kinetics to directly compare and define the effects of different treatments or genetic manipulations on platelet function.

Since the pharmacological inhibitors cannot be used …

The Role Of Dynamin Related Protein 1-Mediated Mitochondrial Dynamics In Colorectal Cancer, Sumati Raj Hasani

Theses and Dissertations--Molecular and Cellular Biochemistry

Cancer cells are known for their ability to adapt variable metabolic programs depending on the availability of specific nutrients. Consequently, metabolic reprogramming has been increasingly recognized as a major mechanism that fuels tumorigenesis and disease progression. Here, we have investigated the role of a pro-fission factor, Dynamin-Related Protein 1 (Drp1), in promoting metabolic adaptation in colon cancer.

Our studies have shown that fatty acid (FAs) uptake alters cellular metabolic pathways in colon cancer cells to favor fatty acid oxidation through the activation of Drp1. Uptake of FAs induces mitochondrial fragmentation by promoting ERK-dependent phosphorylation of Drp1 at the S616 site, …

The Development And Characterization Of Nanobodies Specific To Protein Tyrosine Phosphatase 4a3 (Ptp4a3/Prl-3) To Dissect And Target Its Role In Cancer., Caroline Smith

Theses and Dissertations--Molecular and Cellular Biochemistry

Protein Tyrosine Phosphatase 4A3 (PTP4A3 or PRL-3) is an oncogenic dual-specificity phosphatase that drives tumor metastasis, promotes cancer cell survival, and is correlated with poor patient prognosis in a variety of solid tumors and leukemias. The mechanisms that drive PRL-3’s oncogenic functions are not well understood, in part due to a lack of research tools available to study this protein. The development of such tools has proven difficult, as the PRL family is ~80% homologous and the PRL catalytic binding pocket is shallow and hydrophobic. Currently available small molecules do not exhibit binding specificity for PRL-3 over PRL family members, …

Novel Mechanistic Insight Into Ciliary Regulation: Old Pathways Yield New Mechanisms, Larissa L. Dougherty

Dartmouth College Ph.D Dissertations

Cilia are structures present on most eukaryotic cells which provide important signaling and motile components to cells from early development to fully differentiated and matured cells. Regulation of these structures is critical to proper functioning of the cell and is known to be tied to the cell cycle. Preparation for ciliary assembly following cell cycle exit and ciliary disassembly following cell cycle reentry requires components throughout the cell body and within the cilium to facilitate this process. Here I identify how the cell adapts to ensure modifications to cilia occur for assembly or disassembly using the model organism Chlamydomonas reinhardtii. …

Multilevel Computational Investigation Into The Catalytic Mechanisms Of Matrix Metalloproteinase-1 And Fat Mass And Obesity-Associated Enzyme, Ann Varghese

Dissertations, Master's Theses and Master's Reports

Enzymes are biological macromolecules, typically proteins, that efficiently accelerate the rate of chemical reactions. Their remarkable catalytic power plays a vital role in essential processes across all kingdoms of life. Nowadays, computational chemistry methods provide valuable insights into enzymatic functions aiding our understanding of biological processes and providing advancements in fields such as biomedical sciences, biomimetic catalysis, drug design and biotechnology. This dissertation employs multilevel computational chemistry methods to investigate the structure-function relationships and the catalytic mechanisms of two metalloenzymes -Zn(II)-dependent matrix metalloproteinase-1 (MMP-1) and non-heme Fe(II)/2-oxoglutarate (2OG) dependent fat-mass and obesity-associated (FTO) enzyme. Chapter 2 explores the role of …

Brain Glycogen – Beyond Energy Storage In Glycogen Storage Diseases, Kia H. Markussen

Theses and Dissertations--Molecular and Cellular Biochemistry

Glycogen is a carbohydrate molecule that is traditionally viewed as a convenient and easily accessible energy storage form of glucose. However,emerging evidence supports the role of glycogen as more than a glucose storage form. During the last 20 years, glycogen has been shown to play pivotal roles in learning and memory, signaling events, viscosity, protein glycosylation, and be acritical hallmark in devastating diseases. Not only, does glycogen play a role as an energy substrate and critical metabolite during energy deprivation, glycogen is central for neurotransmitter homeostasis, tumor initiation, and ontributes to proper protein glycosylation in the brain. In this work, …

Metabolic Reprogramming Driven By Ezh2 Inhibition Depends On Cell–Matrix Interactions, Teresa W-M Fan, Jahid M. M. Islam, Richard M. Higashi, Penghui Lin, Christine F. Brainson, Andrew N. Lane

Markey Cancer Center Faculty Publications

EZH2 (Enhancer of Zeste Homolog 2), a subunit of Poly- comb Repressive Complex 2 (PRC2), catalyzes the trimethyla- tion of histone H3 at lysine 27 (H3K27me3), which represses expression of genes. It also has PRC2-independent functions, including transcriptional coactivation of oncogenes, and is frequently overexpressed in lung cancers. Clinically, EZH2 in- hibition can be achieved with the FDA-approved drug EPZ- 6438 (tazemetostat). To realize the full potential of EZH2 blockade, it is critical to understand how cell-cell/cell-matrix interactions present in 3D tissue and cell culture systems in- fluences this blockade in terms of growth-related metabolic functions. Here, we show that …

A Monoadduct Generating Ru(Ii) Complex Induces Ribosome Biogenesis Stress And Is A Molecular Mimic Of Phenanthriplatin, Richard Joseph Mitchell, Sarah M. Kriger, Alexander D. Fenton, Dmytro Havrylyuk, Ankit Pandeya, Yang Sun, Tami Smith, Jason E. Derouchey, David K. Heidary, Edith C. Glazer

Markey Cancer Center Faculty Publications

Ruthenium complexes are often investigated as potential replacements for platinum-based chemotherapeutics in hopes of identifying systems with improved tolerability in vivo and reduced susceptibility to cellular resistance mechanisms. Inspired by phenanthriplatin, a non-traditional platinum agent that contains only one labile ligand, monofunctional ruthenium polypyridyl agents have been developed, but until now, few demonstrated promising anticancer activity. Here we introduce a potent new scaffold, based on [Ru(tpy)(dip)Cl]Cl (tpy = 2,20:60,200-terpyridine and dip = 4,7-diphenyl-1,10-phenanthroline) in pursuit of effective Ru(II )-based monofunctional agents. Notably, the extension of the terpyridine at the 40 position with an aromatic ring resulted in a molecule that …

Bilirubin Levels Are Negatively Correlated With Adiposity In Obese Men And Women, And Its Catabolized Product, Urobilin, Is Positively Associated With Insulin Resistance, Zachary A. Kipp, Mei Xu, Evelyn A. Bates, Wang-Hsin Lee, Philip A. Kern, Terry D. Hinds Jr.

Markey Cancer Center Faculty Publications

Bilirubin levels in obese humans and rodents have been shown to be lower than in their lean counterparts. Some studies have proposed that the glucuronyl UGT1A1 enzyme that clears bilirubin from the blood increases in the liver with obesity. UGT1A1 clearance of bilirubin allows more conjugated bilirubin to enter the intestine, where it is catabolized into urobilin, which can be then absorbed via the hepatic portal vein. We hypothesized that when bilirubin levels are decreased, the urobilin increases in the plasma of obese humans, as compared to lean humans. To test this, we measured plasma levels of bilirubin and urobilin, …

Dysregulated Polycomb Repressive Complex 2 Contributes To Chronic Obstructive Pulmonary Disease By Rewiring Stem Cell Fate, Aria Byrd, Xufeng Qu, Alexsandr Lukyanchuk, Jinpeng Liu, Fan Chen, Kassandra J. Naughton, Tanner Ducote, Xiulong Song, Hannah Bowman, Yanming Zhao, Abigail R Edgin, Chi Wang, Jinze Liu, Christine Fillmore Brainson

Markey Cancer Center Faculty Publications

Aberrant lung cell differentiation is a hallmark of many lung diseases including chronic obstructive pulmonary disease (COPD). The EZH2-containing Polycomb Repressive Complex 2 (PRC2) regulates embryonic lung stem cell fate, but its role in adult lung is obscure. Histological analysis of patient tissues revealed that loss of PRC2 activity was correlated with aberrant bronchiolar cell differentiation in COPD lung. Histological and single-cell RNA-sequencing analyses showed that loss of EZH2 in mouse lung organoids led to lowered self- renewal capability, increased squamous morphological development, and marked shifts in progenitor cell populations. Evaluation of in vivo models revealed that heterozygosity of Ezh2 …