Biochemistry Commons^™

Purification And Activity Assay Optimization Of Bacterial Catalase From Psychrobacter Koprana, Sydney Willis

Honors Program Theses

To date, catalase protein from bacterial species is not the most widely used commercial catalase. Catalase, the enzyme that breaks down hydrogen peroxide in most living organisms, is an invaluable enzyme in the food, agriculture, and pharmaceutical industries. In 2019, a novel species of a psychrotolerant bacterium was discovered in Cold Harbor, NY. This species, Psychrobacter koprana, exhibits highly active catalase. Preliminary data from activity assays demonstrates that P. koprana catalase has the same activity as commercially available catalase. After purification and activity assay optimization, the activity of this catalase has the potential to be more active than other easily …

Effects Of Azadirachta Indica Extract On Inhibition Of Glutamate-Induced Neuronal Cell Apoptosis Via Preventing Excessive Mitophagy Activation And Inhibiting Endoplasmic Reticulum Stress In Ht-22 Cells, Kuljira Mongkolpobsin

Chulalongkorn University Theses and Dissertations (Chula ETD)

Neurodegenerative diseases (NDs) are the age-related diseases which represent a major cause of mortality in aging population nowadays. Previous studies have shown that glutamate, the most abundant excitatory neurotransmitter, significantly increases in extracellular fluid of the patient’s brain and is the cause of neurodegeneration in NDs. The increase of extracellular glutamate elevates reactive oxygen species (ROS) accumulation and calcium (Ca2+) which exacerbate mitochondrial function, followed by inducing MAPK pathway and endoplasmic reticulum (ER) stress, respectively. In addition, Ca2+ overload also triggers calpain, a Ca2+ dependent protease, activity which further stimulates Cdk5/p35/p25 signaling leading to neuronal apoptosis. Azadirachta indica A. Juss. …

Transitions Between The Steps Of Group Iic Intron Forward And Reverse Splicing And Integration Into Dna, Claire Mae Smathers

Graduate Theses, Dissertations, and Problem Reports (ETD)

Group II introns are ancient ribozymes capable of self-excision and mobility into new genomic locations. As the ancestors of both the eukaryotic spliceosome and eukaryotic retroelements, these simple RNA machines serve as excellent models for understanding the mechanisms of both gene splicing and retroelement activity in eukaryotes. Although group II introns have been studied for decades, knowledge of the most unique and arguably evolutionarily relevant class of group II introns, IIC, is limited. Our knowledge is especially limited in terms of understanding how IIC introns mediate the transition between the two transesterification steps of forward splicing and reverse splicing into …

Elucidating The Proteasomal Regulatory Mechanism Of Proteasome Activator Pa28Γ /Regγ, Taylor Ann Thomas

Graduate Theses, Dissertations, and Problem Reports (ETD)

Virtually all cellular processes are precisely regulated by the proteasome which is the primary enzyme responsible for the degradation of misfolded, damaged, or no longer necessary soluble proteins. To prevent any untimely degradation of these target protein substrates and protect the cell, the proteasome is tightly regulated via adaptor proteins, known as proteasomal regulators. There are many classes of proteasomal regulators each with their own unique structures, functions, and effects on protein degradation through the proteasome. One such class is the 11S family of proteasomal regulators which are also referred to as PA26/28, or REG. The 11S family are ATP-independent …

The Musashi Rna Binding Proteins Are Regulators Of Alternative Splicing And Protein Expression In Photoreceptor Cells, Fatimah Kh. Matalkah

Graduate Theses, Dissertations, and Problem Reports (ETD)

The Musashi (Msi) family of RNA binding proteins consists of two paralogs, Msi1 and Msi2, that are highly conserved across species. The two paralogs have emerged as factors that promote stem cell proliferation by post-transcriptionally regulating translation. In addition to their expression in stem cells, the Musashi proteins are also expressed in postmitotic neurons, including the photoreceptor cells. The Musashi proteins have been observed to maintain high expression levels in the postmitotic photoreceptors within the eye of both invertebrates and vertebrates. These observations suggest an additional role in the maintenance of terminally differentiated neurons.

Building upon these observations, we investigated …

Ero1Α Promotes Tumorigenesis In Egfr Driven Nsclc, Brennan D. Johnson

Graduate Theses, Dissertations, and Problem Reports (ETD)

Non-Small Cell Lung Cancer (NSCLC) is a pulmonary malignancy most commonly associated with smoking, or exposure to asbestos or Radon. Approximately, 1.6 Million deaths occur each year due to lung cancer. Lung Cancer is categorized by two main types, Small Cell Lung Cancer (SCLC) and NSCLC. NSCLC accounts for approximately 85% of all lung cancer cases and is subdivided into three sub-categories: Adenocarcinoma, the most common and leading cause of death in the United States; Squamous Cell Carcinoma (SCC), and Large Cell Carcinoma. Though NSCLC treatment regimens have shown increasing clinical benefit over the last two decades with targeted therapies. …

Protein Charge Parameters That Influence Stability And Cellular Internalization Of Polyelectrolyte Complex Micelles, Rachel A. Kapelner, Rachel S. Fisher, Shana Elbaum-Garfinkle, Allie C. Obermeyer

Advanced Science Research Center

Proteins are an important class of biologics, but there are several recurring challenges to address when designing protein-based therapeutics. These challenges include: the propensity of proteins to aggregate during formulation, relatively low loading in traditional hydrophobic delivery vehicles, and inefficient cellular uptake. This last criterion is particularly challenging for anionic proteins as they cannot cross the anionic plasma membrane. Here we investigated the complex coacervation of anionic proteins with a block copolymer of opposite charge to form polyelectrolyte complex (PEC) micelles for use as a protein delivery vehicle. Using genetically modified variants of the model protein green fluorescent protein (GFP), …

Sequential Block Copolymers Of Polyisobutylene And Polyolefins, Manwel Labib

Williams Honors College, Honors Research Projects

A two-step approach will be utilized to synthesize random polyolefin multiblock-copolymers. This strategy takes advantage of a,w-terminated telechelic polyolefins. Polypropylene (iPP)/polyethylene (PE) are picked because of their strength, and polyisobutylene (PIB) because of its hemocompatibility. This copolymer is theorized to make for robust bio-inert plastic, which can be used for surgical mesh implants.

Characterizing The Post-Translational Modifications Of The Pro-Oncogenic Type Ii Transmembrane Serine Protease Tmprss13, Carly Elizabeth Martin

Wayne State University Dissertations

TMPRSS13, a type II transmembrane serine protease discovered at the turn of the century, has recently been shown to be significantly overexpressed in both breast cancer (BCa) and colorectal cancer (CRC), and to mediate chemoresistance in cell lines from both cancer types. Furthermore, loss of TMPRSS13 in a genetic model of mouse mammary carcinoma significantly reduced tumor burden and growth rate, and increased overall tumor-free survival. Its location on the cell surface as well as its low expression in normal breast and colon make TMPRSS13 an attractive candidate as an oncogenic biomarker and therapeutic target in cancer. However, little is …

Fluorescent Cellular Assays For Kinase Inhibitors, Myar Mohamed

Graduate Research Theses & Dissertations

One of the most successful and fastest growing groups of kinase inhibitors are small molecules that compete with ATP binding. Kinase function is closely related to many diseases, specifically cancer. Kinases within living cells are essential elements in signaling cascades and post-translational modifications. However, actual kinase activity and the efficacy of its inhibitors in living systems are hard to evaluate. A way to assess inhibitor activity is through cellular assays that directly report the inhibitor’s engagement in native environments. Our goal is to develop a simple near-infrared (NIR) fluorescent HTS-compatible cellular assay for kinase inhibitor profiling in native cellular environments. …

Synthesis Of Rna Nucleotides Under Probable Prebiotic Conditions, Ryan Stimson

Williams Honors College, Honors Research Projects

RNA being composed of multiple covalently linked nucleotides is thought to have been a precursor to life circa 4.3-3.8 billion years ago. Non-enzymatically formed adenosine monophosphate (AMP), more specifically, is a vitally important subtopic of the self-assembly of the first RNA sequence. The goal of this study was to synthesize AMP non-enzymatically under benign conditions that are likely to have existed on early Earth. In this experiment, 3’,5’-cAMP was successfully formed using wet-dry cycles at 80°C paired with the minerals zeolite beta, hydroxyapatite, and aerosil 300 in the presence of adenosine, urea, and pyrophosphate. A nuclear magnetic resonance spectrometer was …

The Role Of Shoc2 In Embryonic Development, Rebecca G. Norcross

Theses and Dissertations--Molecular and Cellular Biochemistry

The canonical ERK1/2 signaling cascade regulates cellular functions critical in vertebrate embryonic development such as proliferation, apoptosis, differentiation, and migration. Thus, its signals are controlled by a variety of mechanisms. Scaffold proteins are considered central to the mechanisms regulating the transmission of the ERK1/2 signals. Yet, their functions in development nor the molecular mechanisms by which they exert their control are not well understood.

This study focuses on the essential regulator of ERK1/2 signals during development – the scaffold protein Shoc2. Loss of Shoc2 leads to early embryonic lethality in mice and zebrafish. Germline mutations in the shoc2 gene result …

Structural Basis For Reversible Glucan Phosphorylation By Glucan Dikinases And Glucan Phosphatases, Tiantian Chen

Theses and Dissertations--Molecular and Cellular Biochemistry

Plants store glucose in the form of starch, an insoluble macromolecule that is synthesized and degraded diurnally. Glucan phosphatases play a critical role in starch breakdown, working with glucan dikinases in a cyclic phosphorylation and dephosphorylation. Herein, we present a novel glucan phosphatase Like SEX Four3 (LSF3) from Physcomitrella patens. Structural and enzymatic studies demonstrate that LSF3 is a dimeric glucan phosphatase that displays robust specific glucan phosphatase activity. Dimerization is shown to be essential for LSF3 stability and function. Structure-guided bioinformatic analysis shows that LSF3 is found in early land plants and green algae.

Building upon our understanding of …

A Multidisciplinary Characterization Of The Enzymology And Biology Of Reversible Glucan Phosphorylation In Toxoplasma Gondii , Robert Murphy

Theses and Dissertations--Molecular and Cellular Biochemistry

Toxoplasma gondii is an opportunistic, protozoan parasite of all warm-blooded animals, infecting roughly one-third of humans worldwide. Humans acquire infections by consuming T. gondii tissue cysts in undercooked meat or from oocysts shed in cat feces. Encysted parasites convert into rapidly growing tachyzoites that disseminate throughout the body, defining the acute phase of infection. Under host immune pressure, tachyzoites convert into bradyzoites that populate tissue cysts found in CNS or muscle tissue and persist for the lifetime of the host, defining the chronic phase of infection. Tissue cysts are responsible for transmission via carnivory, but also possess the ability to …

Building Digital Twins Of The Human Immune System: Toward A Roadmap, Reinhard Laubenbacher, Anna Niarakis, Tomas Helikar, G. An, B. Shapiro, R. S. Malik-Sheriff, T. J. Sego, P. Macklin, J. A. Glazier

Department of Biochemistry: Faculty Publications

Digital twins, customized simulation models pioneered in industry, are beginning to be deployed in medicine and healthcare, with some major successes, for instance in cardiovascular diagnostics and in insulin pump control. Personalized computational models are also assisting in applications ranging from drug development to treatment optimization. More advanced medical digital twins will be essential to making precision medicine a reality. Because the immune system plays an important role in such a wide range of diseases and health conditions, from fighting pathogens to autoimmune disorders, digital twins of the immune system will have an especially high impact. However, their development presents …

Feedlot Diets Containing Different Starch Levels And Additives Change The Cecal Proteome Involved In Cattle’S Energy Metabolism And Inflammatory Response, Leone Campos Rocha, Andrey Sávio De Almeida Assunção, Renata Aparecida Martins, Victor Valério De Carvalho, Alexandre Perdigão2, Marília Afonso Rabelo Buzalaf, Jiri Adamec, Camila Pereira Braga, Danilo Domingues Millen, José Cavalcante Souza Vieira, Pedro De Magalhães Padilha

Department of Biochemistry: Faculty Publications

Diets for feedlot cattle must be a higher energy density, entailing high fermentable carbohydrate content. Feed additives are needed to reduce possible metabolic disorders. This study aimed to analyze the post-rumen effects of different levels of starch (25%, 35%, and 45%) and additives (monensin or a blend of essential oils and exogenous α-amylase) in diets for Nellore feedlot cattle. The cecum tissue proteome was analyzed via two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and then differentially expressed protein spots were identified with liquid chromatography–tandem mass spectrometry (LC–MS/MS). The use of blends of essential oils associated with α-amylase as a feed additive promoted …

The Role Of Irf-1 In Spontaneous Mouse Glioma, Aakash B. Vaidya

Theses and Dissertations

Glioblastoma Multiforme has been shown to be one of the deadliest primary brain cancers. One of the reasons why GBM is so deadly, is a unique immunosuppressive tumor microenvironment that promotes GBM growth and progression. Both astrocyte and microglia have been implicated in immunosuppression. In this study, we explored the role of Interferon Regulatory Factor 1 (IRF-1) in astrocytes and glioma cells on the growth of spontaneous glioma tumors. IRF-1 is regulated by the JAK/STAT pathway and induces expression of Programmed death ligand 1 (PD-L1). PD-L1 downregulates immune responses to glioma. We found that IRF-1 had no effect on spontaneous …

Development Of Novel Pyridazine Derivatives And Drug Delivery Systems Against Dengue, Janae A. Culmer

College of Graduate Studies: Theses & Dissertations

The lack of approved vaccines, medications and treatment regimens has significantly contributed to the rapid spread of mosquito-borne viruses such as Dengue and Zika virus. The complex immunopathology of these viruses presents limitations for the development and implementation of a definitive, safe and effective approach to combat infections.Previous research has demonstrated that vector control strategies such as the elimination of larval habitats, larviciding with insecticides, the use of biological agents and the application of adulticides have been unsuccessful in the reduction of viral transmission leading to the need for the continued development of antivirals. This research proposes an approach for …

Structural And Functional Characterization Of Two Poly(Aspartic Acid) Hydrolases, Amanda Jansch

College of Graduate Studies: Theses & Dissertations

Due to the accumulation of polymers in the environment, biodegradable alternatives should be used in place of commonly used polymers like poly(carboxylates). Poly(carboxylates) are water-soluble polymers (WSPs) that make up a variety of consumer products, such as detergents, descaling agents, and superabsorbent materials commonly found in diapers and feminine hygiene products. While the visible accumulation of these products may not be obvious, it is necessary to reduce the amount entering the environment. Poly(aspartic acid) (PAA) is an alternative WSP that is biodegradable through the action of three different enzymes, PahZ1_KT-1, PahZ2_KT-1, and PahZ1_KP-2. Originally …

The Impact Of Plant Secondary Metabolites On Auxin And Cytokinin Signaling, Timothy E. Shull

Theses and Dissertations--Plant and Soil Sciences

Secondary metabolites are a broad class of specialized compounds that mediate plant-environment interactions and mitigate stress. It is increasingly clear that many phenylalanine-derived secondary metabolites are nearly indispensable for plant survival and that plants adjust their growth according to their secondary metabolic outputs. Consequently, many phenylalanine-derived secondary metabolites have influence over hormone activity. For instance, multiple phenylpropanoid intermediates and catecholamines alter the sensitivity of plants to the central hormone auxin, which in concert with cytokinin directs most aspects of plant growth and development. This dissertation reviews previous research on the influence of phenylpropanoid intermediates and catecholamines on plants, with a …