Life Sciences Commons^™

Development Of Multivalent Dna-Peptide Nucleosome Mimetics And Multi-Domain Protein Inhibitors That Directly Or Indirectly Target The E3 Ligase Uhrf1, Li Gu

University of the Pacific Theses and Dissertations

UHRF1 is an E3 ubiquitin ligase and a key epigenetic regulator establishing a crosstalk between DNA methylation and histone modification. Despite the important biochemical role of UHRF1 in cells, its overexpression has been found in almost all primary cancer types including breast cancer, lung cancer and so on. Numerous evidence indicates a strong link between tumorigenesis and UHRF1 overexpression, supporting its potential as a universal biomarker for cancer. However, UHRF1 is “yet-to-be drugged” and no highly potent chemical probes have been developed to target UHRF1 to date. In this study, we proposed two drug design approaches for UHRF1. The first …

The Role Of Rad51 In Trichomonas Vaginalis, Dominique Hall

University of the Pacific Theses and Dissertations

Drug resistance to the current treatments on the market is on the rise, therefore there is strong interest in understanding what could be causing the resistance, how resistance could be spreading through the population, and finding some possible new drug targets. One protein of interest is Radiation Sensitive Protein 51 (Rad51). It is a protein that is involved in homologous recombination as well as other processes such as DNA damage repair. While Trichomonas vaginalis traditionally has been known to replicate via binary fission, a modified form of closed mitosis, there is some evidence that meiosis, or at least some form …

Microbial Community Analysis: Biofilm Inhibition & Algae Associated Community Structure, Michelle V. Fong

University of the Pacific Theses and Dissertations

Natural products chemistry is the pursuit of bioactive small molecules from living organisms. These can be classified as primary metabolites if they are essential to survival, and secondary metabolites if they are accessory, playing a role in communication, defense, recruitment, etc.. Natural products have made a significant contribution to society – of 1,881 FDA-approved drugs from 1981 to 2019, 4% were pure natural products, 19% were natural products derived, and 3% were synthetic drugs with a natural products pharmacophore targeting a wide range of diseases and infections (Newman & Cragg, 2020). Pharmacophores are structural components of drugs that are responsible …

Post-Translational Modification And Degradation Mechanisms Of The Aryl Hydrocarbon Receptor, Yujie Yang

University of the Pacific Theses and Dissertations

The aryl hydrocarbon receptor (AHR) is a transcription factor first discovered to be activated by exogenous ligands, such as dioxins, and helps promote downstream gene (e.g. CYP1A1) transcription to metabolize the toxicants. With the reports of various AHR targets genes, the expression levels and activities of AHR have been implicated in many physiological and pathological situations. Understanding how AHR protein level is regulated would provide more information to target AHR. AHR stays in the cytosol in the absence of ligand in a complex with HSP90, p23 and XAP2. After ligand activation, AHR translocates into the nucleus, fulfilling its transactivation function …

Development Of Linked-Domain Protein Inhibitors Of The E2-Conjugating Enzyme Ube2d, Anneroos E. Nederstigt

University of the Pacific Theses and Dissertations

In most eukaryotic organisms, the ubiquitination pathway is one of the most important and versatile signaling systems in use. It is integral to processes such as protein degradation and homeostasis, DNA repair cell cycle regulation, signaling and regulation, epigenetics, and many more. Ubiquitin (Ub) is a short polypeptide of 8.6 kDa, 76 residues that functions as a reversible post-translation modification (PTM). It furthermore contains 7 different lysine residues (K6, K11, K27, K29, K33, K48, K63), all of which can form isopeptide linkages with one another to link individual Ub moieties to form unique polyUb chains onto substrates. The type of …

A Proteomic Analysis Of Corydoras Sterbai Secretions And Tissues, Erik Powell Wictor

University of the Pacific Theses and Dissertations

Defensive mechanisms vary widely in the animal kingdom ranging from physical defenses like spines to chemical defenses such as toxins. Toxins in these secretions and tissues can fluctuate from enzymes to lipids to uncharacterized chemicals. Next generation -omics technology and mass spectrometry are extremely important in analyzing these samples because of their ability to distinguish minute amounts of toxic substance within a complicated sample. The goal of this experiment was to look at secretions and tissues from Corydoras sterbai. All samples in this study were proteolyzed using a mixture of Trypsin and Lys-C, fractionated, and run through nanoLC-MS/MS analysis using …

Proteomic Analysis Of Fetal Rat Neural Stem Cells After Treatment With Hericium Erinaceus, Bright Adam Test

University of the Pacific Theses and Dissertations

The fungus, Hericium erinaceus, has outstanding chemical properties, displaying health benefits in digestive, hepatic, and nervous tissues. Its ease of accessibility and use makes it one of the most common substances used for treatment in Eastern medicine. More and more recent research is confirming the incredible health benefits of this fungus, especially the impact that is seen on nervous tissue growth and recovery post-treatment. Such neurite outgrowth and myelin sheath regeneration could illustrate the beginning of the cure to lifelong neurodegenerative diseases such as Multiple Sclerosis. In this first-of-its-kind study, we cultured and differentiated fetal rat neural stem cells while …

Structural Characterization Of Black Widow Spider Dragline Silk Proteins Crp1 And Crp4, Mikayla Shanafelt

University of the Pacific Theses and Dissertations

Spider dragline silk is a biomaterial with outstanding material properties, possessing high-tensile strength and toughness. In nature, dragline silk serves a central role during spider locomotion and web construction. Today, scientists are racing to elucidate the molecular machinery governing silk extrusion, attempting to translate this knowledge into a mimicry process in the laboratory to create synthetic fibers for a wide range of different applications. During extrusion, it has been established that biochemical and mechanical forces govern spidroin folding, aggregation, and assembly. In black widow spiders, at least 7 different proteins have been identified as constituents of dragline silk fibers. These …

Knob-Socket Investigation Of Stability And Specificity In Alpha-Helical Secondary And Quaternary Packing Structure, Taylor Renee Rabara

University of the Pacific Theses and Dissertations

The novel knob-socket (KS) model provides a construct to interpret and analyze the direct contributions of amino acid residues to the stability in α-helical protein structures. Based on residue preferences derived from a set of protein structures, the KS construct characterizes intra- and inter-helical packing into regular patterns of simple motifs. The KS model was used in the de novo design of an α-helical homodimer, KSα1.1. Using site-directed mutagenesis, KSα1.1 point mutants were designed to selectively increase and decrease stability by relating KS propensities with changes to α-helical structure. This study suggests that the sockets from the KS Model can …

Development Of A Biomarker Panel For Identifying Stressed Marine Mammals, Laura Pujade

University of the Pacific Theses and Dissertations

Increasing anthropogenic disturbance in marine ecosystems such as fishing, oil-drilling, and noise pollution can have detrimental effects on the reproduction and survival of apex predators such as marine mammals. Stress activates the hypothalamic-pituitary-adrenal (HPA) axis, resulting in increased circulating glucocorticoid (GCs) hormones, which alter expression of target genes encoding metabolic enzymes and other mediators of stress. Prolonged HPA axis stimulation may increase catabolism of nutrient stores and suppress immune and reproductive functions, impacting the fitness of marine mammals. GCs measurements are used to identify wild animals experiencing stress. However, these measurements may not be sensitive enough to distinguish between an …

Evaluating Methods Of Obtaining Male Pheromone From Hymenochirus Sp. Using Analytical Chemistry, Vincent Wing-Kun Leung

University of the Pacific Theses and Dissertations

Male Hymenochirus sp. frogs are known to release pheromone that attracts females of the same species. Four methods for collecting secretions containing pheromone in Hymenochirus sp. were tested: norepinephrine injection, gonadotropin-releasing hormone injection, homogenization of gland tissue, and electrostimulation of the skin over the breeding gland area. The samples collected were analyzed using high-performance liquid chromatography (HPLC) and mass spectrometry. The HPLC chromatograph for the male norepinephrine sample contained a peak at 6.4 min that was not in the female norepinephrine sample HPLC chromatograph. The male norepinephrine sample mass spectrum had a peak of m/z 292.0 not in the female …

Investigating The Effect Of Rutaecarpine On The Benzo[A]Pyrene-Induced Dna Damage In Vitro, You Li

University of the Pacific Theses and Dissertations

Benzo[a]pyrene (BaP), is one of the most potent mutagens and carcinogens known. It requires metabolic activation through cytochrome P450 (CYP)1A1 to yield the ultimate carcinogenic metabolite, benzo[a]pyrene-7,8-dihydrodiol-9,10-epoxide (BPDE). BPDE can bind to DNA and form predominantly covalent (+) trans adducts at the N2 position of guanine causing DNA damage. Rutaecarpine (RTC) is an herbal medicine that has been used to treat several diseases such as headache, hypertension, gastrointestinal disorders, amenorrhea, and anti-inflammation. It has also been reported as a potent inducer of CYP enzymes, including CYP1A1, and CYP1A2. The mechanisms underlying up-regulation of CYP1A1 by RTC is dependent on aryl …

Dna Lesions Produced From The Reaction Of Diols And 5-Formylcytosine And Their Effects On Dna Replication, Brock Allen

University of the Pacific Theses and Dissertations

Nucleic acids are complex macromolecules that are susceptible to both endogenous and exogenous damage. This study explored damage resulting from interactions with environmental nucleophilic toxins, such as a variety of diols and amines found in industry. These nucleophiles can react with electrophilic groups, such as 5-formylcytosine. 5-formylcytosine is an oxidation product of the epigenetic base 5-methylcytosine. It is typically removed by thymine DNA glycosylase (TDG) but is known to accumulate in the genome, making the formyl group susceptible to attack. In this study we used GC/MS and ESI-MS to show that DNA lesions from the nucleophilic addition reaction of toxins …

Investigations On Cancer Cell Biological Effects Of Cdk8 Inhibitor Q-12, Zhixin Lu

University of the Pacific Theses and Dissertations

Over the past two decades, protein kinases have been intensively investigated as targets to treat neoplastic diseases. Many protein kinase inhibitors not only have therapeutic potential but are becoming invaluable reagents for the study of cell signaling.

We aspired to use our Cyclin-Dependent Kinase 8 inhibitor, Q-12, as a probe for biomarker discovery for CDK8 inhibitor sensitive tumor types. Q-12 shows potent inhibition of cell viability and induction of apoptosis process in some triple-negative breast cancer and colorectal cancer cell lines in vitro. Western blot results indicate that the reduction of STAT1 phosphorylation could be a robust indicator of CDK8 …

Influence Of The Estrous Cycle And Female Sex Hormones On Ghb Toxicokinetics, Hao Wei

University of the Pacific Theses and Dissertations

Gamma-Hydroxybutyrate (GHB) is an endogenous short-chain fatty acid formed from Gamma-aminobutyric acid (GABA). Clinically, GHB is marketed in the United States as Xyrem to treat narcolepsy with cataplexy and in Europe for the treatment of alcohol withdrawal and narcolepsy. However, the illicit use and abuse of GHB occurs due to its sedative/hypnotic and euphoric effects. Monocarboxylate transporters (MCTs and SMCTs) are integral membrane proteins that control the bidirectional transport of endogenous substrates including lactate, acetate and pyruvate. They have also been found to transport and mediate the clearance and distribution of GHB. MCTs demonstrate a wide tissue distribution, including brain, …

Design And In Vitro Characterization Of Lipids With A Ph-Sensitive Conformational Switch And Their Liposomes For Anticancer Drug Delivery, Shen Zhao

University of the Pacific Theses and Dissertations

The traditional anticancer drugs are distributed in vivo through systemic blood circulation with a very small portion reaching the tumor site. Targeted drug delivery systems are developed in efforts to concentrate the drug molecules in the tissue of interest while reducing the drug distribution to healthy tissues to reduce the side effects. Liposomes are colloidal systems composed of amphiphilic molecules that assemble into vesicle structures in aqueous media. They are common carriers for targeted drug delivery with the advantages of low toxicity, low immunogenicity and the ability of encapsulating both lipophilic and hydrophilic drugs.

Prior research indicated the advantages of …

Peptide-Drug Conjugate For Her2-Targeted Drug Delivery, Yan Wang

University of the Pacific Theses and Dissertations

Recent strategies for anticancer drug design have been focused on utilizing antibody as a drug or targeted moiety for targeted drug delivery. Antibody−drug conjugates (ADCs) have become a promising new class of targeted therapeutic agents for treatment of cancer. ADCs are designed to preferentially direct a cytotoxic drug to a cell-surface antigen recognized by an antibody. However, there are some challenges in developing ADCs, such as limited solid tumor penetration, high manufacturing costs and antibody-drug stoichiometry. Smaller molecules such as peptides have been shown to specifically bind to cancer related targets. These peptides can be used to form peptide-drug conjugates …

Determining The Role Played By Aryl Hydrocarbon Receptor (Ahr) In The Colon Carcinoma Tumor Model, Poonam Yakkundi

University of the Pacific Theses and Dissertations

Aryl hydrocarbon receptor (AHR), commonly known as an environmental sensor involved in the metabolism and elimination of xenobiotic substances, is also an important modulator in the development and functioning of the immune system. AHR expression is varied in the T cell subsets with the highest expression in T-helper 17 and T regulatory cells. Work from many researchers has suggested that AHR can act as a tumor promoter or a tumor suppressor depending on the tumor type. Our goal is to understand the role played by AHR in MC38 syngeneic colon carcinoma tumor model. In the absence of AHR, MC38 tumor …

The Synthesis Of Various Substituted 3-Amino-7-Hydroxy-2,2-Dimethyltetralins And Their Opioid-Related Activities, David Alan Lippman

University of the Pacific Theses and Dissertations

A series of aminotetralones and aminotetralins were synthesized from the common intermediate F, 3-amino-2,2-dimethyl-7-methoxy- 1-tetralone. The final compounds derived from F were simple substituted and/or reduced analogues. The products would allow a progressive structure activity relationship to be drawn based on pharmacological testing.

The common intermediate F was synthesized utilizing a six step procedure starting with p-methoxyphenylacetic acid. The overall yield from the precursor to the F:HC1 was 25%. Compound F was either O-demethylated to form 3-amino-2,2-dimethyl-7-hydroxy-l-tetralone (I) or was dimethylated on the amine and subsequently O-demethylated to yield the 3-dimethylamino-7-hydroxy-2,2-dimethyl-l-tetralone (J). The last major modification was the reduction of …

The Chemical Analysis Of Velella Lata Float, Ralph Lee Gainey

University of the Pacific Theses and Dissertations

Everything should be ultimately explainable in terms of the components of which it is composed. In the animal kingdom well over ninety-five percent of all recognized species are invertebrates, a distinction based on connective tissues, though most of our efforts have been directed towards vertebrates for reasons of convenience and closeness to man. Investigation of the various chemicals which make up plants and animals have been diverse, allowing us to get a general picture of what molecules to expect at each state of the evolutionary progression, but for now animal is the information complete, and for invertebrates the information is …

A Study Of Methods Of Determining The Rate Of Acid Hydrolysis Of Wheat Gluten, Angus V. Henrickson

University of the Pacific Theses and Dissertations

Because of the nutritious value of sodium glutamate and its meat-Like flavor, won 18 very pleasing to most people, and hence Its demand if it were properly promoted, and because of the abundance of protein in accessible form for its manufacture, it is only reasonable to assume that if too optimum continuous of protein hydrolysis were found, tho manufacturing metnous could be made a.highly successful enterprise.