Biochemistry Commons^™

Inflammation And Tumor Progression: The Differential Impact Of Saa In Breast Cancer Models, Daniel Wilhelm Olivier, Carla Eksteen, Manisha Du Plessis, Louis De Jager, Lize Engelbrecht, Nathaniel Wade Mcgregor, Preetha Shridas, Frederick C. De Beer, Willem J. S. De Villiers, Etheresia Pretorius, Anna-Mart Engelbrecht

Saha Cardiovascular Research Center Faculty Publications

Background: Previous research has shown that the Serum Amyloid A (SAA) protein family is intricately involved in inflammatory signaling and various disease pathologies. We have previously demonstrated that SAA is associated with increased colitis disease severity and the promotion of tumorigenesis. However, the specific role of SAA proteins in breast cancer pathology remains unclear. Therefore, we investigated the role of systemic SAA1 and SAA2 (SAA1/2) in a triple-negative breast cancer mouse model.

Methods: Syngeneic breast tumors were established in wild-type mice, and mice lacking the SAA1/2 (SAADKO). Subsequently, tumor volume was monitored, species survival determined, the inflammatory profiles of mice …

Development Of A Diaryl Oxazole-Based Cleavable Linker For Peptides, Evan Wolff

Honors Theses

The development of new cleavable linkers increases the diversity of compatible conditions for peptide discovery platforms. Potential applications for these linkers include high-throughput pharmaceutical candidate screening when utilized in Peptide Encoded Libraries (PELs). This thesis describes the development of a bifunctional diaryl oxazole-based cleavable linker that may be incorporated into compounds through Solid-Phase Peptide Synthesis (SPPS). This oxazole-based linker may be rapidly cleaved by cerium ammonium nitrate in aqueous conditions and is compatible with most natural amino acids and a variety of unnatural amino acids. This linker represents the first single-electron oxidant labile linker described to our knowledge and it …

N(Alpha)-Acetyltransferase 40-Mediated Histone Acetylation Plays An Important Role In Ecdysone Regulation Of Metamorphosis In The Red Flour Beetle, Tribolium Castaneum, Sharath Chandra Gaddelapati, Smitha George, Anilkumar Moola, Karthi Sengodan, Subba Reddy Palli

Entomology Faculty Publications

Histone acetylation, a crucial epigenetic modification, is governed by histone acetyltransferases (HATs), that regulate many biological processes. Functions of HATs in insects are not well understood. We identified 27 HATs and determined their functions using RNA interference (RNAi) in the model insect, Tribolium castaneum. Among HATs studied, N-alpha-acetyltransferase 40 (NAA40) knockdown caused a severe phenotype of arrested larval development. The steroid hormone, ecdysone induced NAA40 expression through its receptor, EcR (ecdysone receptor). Interestingly, ecdysone-induced NAA40 regulates EcR expression. NAA40 acetylates histone H4 protein, associated with the promoters of ecdysone response genes: EcR, E74, E75, and HR3, and causes an increase …

The Mechanoreceptor Piezo Is Required For Spermatogenesis In Bombyx Mori, Zhongjie Zhang, Xiaojing Liu, Bo Hu, Kai Chen, Ye Yu, Chenxin Sun, Dalin Zhu, Hua Bai, Subba Reddy Palli, Anjiang Tan

Entomology Faculty Publications

Background The animal sperm shows high diversity in morphology, components, and motility. In the lepidopteran model insect, the silkworm Bombyx mori, two types of sperm, including nucleate fertile eupyrene sperm and anucleate unfertile apyrene sperm, are generated. Apyrene sperm assists fertilization by facilitating the migration of eupyrene spermatozoa from the bursa copulatrix to the spermatheca. During spermatogenesis, eupyrene sperm bundles extrude the cytoplasm by peristaltic squeezing, while the nuclei of the apyrene sperm bundles are discarded with the same process, forming matured sperm.

Results In this study, we describe that a mechanoreceptor BmPiezo, the sole Piezo ortholog in B. mori, …

Illuminating Function And Enabling Inhibition At The Protein-Membrane Interface Of Glutathione Peroxidase 4., Courtney L. Labrecque

Theses and Dissertations

Membrane proteins act as gateways to cells and are responsible not only for signaling, lipid transport, and cellular homeostasis, but they are also integral in disease pathologies. One class of membrane proteins, peripheral membrane proteins (PMPs), reside in aqueous compartments of the cell until they are recruited to the membrane to perform their function. Glutathione peroxidase 4 (GPx4) is a PMP enzyme responsible for engaging the membrane and reducing lipid hydroperoxides, thereby preventing cellular death via ferroptosis. Due to its central function surrounding ferroptosis, GPx4 is an interesting drug target that has recently gained interest for inflammatory diseases as well …

Functionalized Gold Nanoparticles And Halogen Bond Interactions With Neonicotinoid Pesticides, Molly Mccuen “Mackey” Sherard

Honors Theses

Neonicotinoid (NN) pesticides have emerged globally as one of the most widely used agricultural tools for protecting crops from pest damage and boosting food production. Unfortunately, some NN compounds, such as extensively employed imidacloprid-based pesticides, have also been identified as likely endangering critical pollinating insects like honey bees. To this end, NN pesticides pose a potential threat to world food supplies. As more countries restrict or prohibit the use of NN pesticides, tools are needed to effectively and quickly identify the presence of NN compounds like imidacloprid on site (e.g., in storage areas on farms or pesticide distribution warehouses). This …

Impact Of Hdac Inhibitors On The Efficiency Of Cardiomyocyte Differentiation, Lauren Mary Sargent

Honors Theses and Capstones

Heart disease and injury is the leading cause of death worldwide, with much of its severity caused by the low regenerative capacity of cardiomyocytes (CMs). One of the strategies to counteract the poor regeneration of CMs is the production of CMs via differentiating stem cells. However, the low efficiency of obtaining CMs from stem cells is an issue because there are numerous inconsistencies in the process. Histone deacetylase (HDAC) inhibitors have been researched as ways to increase efficiency of CM differentiation by increasing histone acetylation, and thereby allowing differentiation to occur more efficiently. In this study, the HDAC inhibitor, trichostatin …

Immune Signaling And Pathogenesis Of Enterocytozoon Hepatopenaei Infection In Pacific White Shrimp Litopenaeus Vannamei, Nutthapon Sangklai

Chulalongkorn University Theses and Dissertations (Chula ETD)

Enterocytozoon hepatopenaei (EHP) is an intracellular microsporidian parasite causing hepatopancreatic microsporidiosis (HPM), a disease that impairs the digestion and nutrients absorption of shrimp and leads to growth retardation and size variation. Our studies aim to comprehensively investigate the host’s immune responses to the EHP infection and the pathogenesis of the parasite. It was found that genes in Toll and JAK/STAT pathways, as well as antimicrobial peptides, were highly upregulated upon the EHP infection. Importantly, suppression of the JAK/STAT pathways resulted in a significant reduction of the c-type lysozyme (LvLyz-c) expression and the elevation of EHP copy numbers. These indicate a …

Cd46 Isoforms And Viral Receptor For Adenovirus Type 64d, Corina Stasiak

Honors Theses

Adenovirus Type 64 (Ad.64) belongs to the adenovirus subgroup D, which causes epidemic keratoconjunctivitis (EKC), otherwise known as viral pink eye. There is currently no known effective treatment for EKC. Membrane Cofactor Protein (CD46) is an integral membrane glycoprotein that, in previous studies, has been identified as a protein receptor for the closely related Ad.37. It has been determined that Ad.64 uses CD46 as a receptor on the cell surface in HeLa cells. CD46 is alternatively spliced when expressed to have different isoforms of interest, including the BC and C isoforms. Certain cell types, like A549 lung carcinoma cells, express …

Cd46 Is A Protein Receptor For Human Adenovirus Type 64, Alexander Michael Robertson

Honors Theses

Adenoviruses are important gene delivery vectors and causative agents for a variety of human diseases such as the common cold and gastrointestinal infections. Human adenovirus type 64 (Ad64; formerly 19c) and type 37 are associated with epidemic keratoconjunctivitis. Based upon its high homology and similar disease tropism to Ad37, we hypothesized that Ad64 would have the same protein receptor, CD46 (membrane cofactor protein), as Ad37. We show that a recombinant Ad64 containing an enhanced Green Fluorescent Protein transgene (Ad64.eGFP) enters Chinese hamster ovary cells expressing human CD46 (CHO-CD46) on the surface. Entry into human cervical carcinoma (HeLa) cells is increased …

Structural Phylogenetics Of A Family Dna Polymerases, Yagmur Bingul

Honors Theses

The transition from the RNA to the DNA world stands as an important event, demanding the emergence of enzymatic activities for DNA precursor synthesis, retro-transcription of RNA templates, and replication of single and double-stranded DNA molecules. The distribution of protein families associated with these activities across the three domains of life—Archaea, Eukarya, and Bacteria—adds layers of complexity to the narrative. While Archaea and Eukarya often share similar protein structures, structural biology shows homologous, but distinct, structures in Bacteria. On the other hand, viral polymerases emerge as a crucial part of genome replication and transcription. Their versatility, including RNA-dependent RNA polymerase, …

Heterocycles As Peptide-Based Cleavable Linkers, John Blobe

Honors Theses

As cancer cases continue to rise, the need for advancing the treatment options for cancer is ever increasing. Current cancer therapeutics, while effective at treating localized cancers and a fraction of advanced cancers, generally lack the specificity needed to target more advanced cancers. Recent advancements in cancer treatments have leveraged antibodies to target certain cancers. A class of drugs that utilize antibodies to deliver anti-cancer therapy preferentially to cancer cells, termed antibody-drug conjugates (ADCs), have been quite effective in treating certain advanced forms of certain cancers. These ADCs could be more effective if they could allow for the facile release …

Investigating A Potential Protein-Protein Interaction Between Transcription Factor Pax6 And Ribosomal Protein S20 (Rps20), Modupe Oladayo

All Master's Theses

The neocortex is the largest region of mammalian brains and is responsible for the complex cognitive abilities and behaviors of mammals. The neocortex of mature mammals is divided into concise areas, which process sensory information from ears, eyes, and touch receptors, and regulate conscious movement of muscles. The combined graded expressions of several transcription factors over the embryonic neocortical ventricular zone regulates the sizes of these functional areas in the adult neocortex. Although progress has been made in understanding how transcription factors affect neocortical patterning, additional research is required to fully understand the underlying molecular mechanism(s), which will contribute to …

Whole Genome Crispr-Cas9 Screens Identify Genes Contributing To Viral Entry And Phagocytosis, Md Saddam Hossain

Electronic Theses and Dissertations

CRISPR/Cas9 is a revolutionary technique for genome editing where Cas9 nucleases can be targeted to specific genomic sites by single-guide RNAs (sgRNAs) containing roughly 20-nucleotide sequences that are complementary to the target region. Double strand breaks created by Cas9 are repaired through non-homologous end-joining (NHEJ) in most cells, resulting in insertions and deletions leading to frame shift mutations in coding regions. Thus, the CRISPR-Cas9 system can be exploited for systematic evaluation of gene function relationships by whole genome screening. We also developed a CRISPR whole‐genome screen and counter‐screen strategy based on a pseudoviral platform that allowed identification of genes specific …

Using Virus Like Particle Conjugates Of Synthetic Targeting Compounds To Deliver Chemotherapeutic Drugs To Cancer Stem Cells, Austen W. Kerzee

Chemistry Theses

Cancer stem cells are a type of cell that have the properties of both cancer cells and stem cells. They can differentiate into other types of cancer cells, are resistant to conventional chemotherapeutics, and seem to contribute greatly to the metastasis and recurrence of cancer. Due to these properties, eliminating cancer stem cells would be greatly beneficial in the treatment of cancer. While there have been approved therapeutic methods for the removal of a few of the cancer stem cells types, treatment for most types of cancer stem cells are still in the experimental phase and have yet to be …

Atg11 And Atg9 Interaction In Selective Autophagy, Chimi Dolker Sherpa

Master's Theses and Doctoral Dissertations

Selective autophagy, induced by cellular stresses, degrades/recycles a specific cargo. Ithelps prevent diseases like Parkinson’s, Huntington's, cancer, and bacterial infections. It involves the formation of an autophagosome, a double-membrane vesicle that takes the cargo to the vacuole/lysosome for degradation. Atg11, the central organizer of selective autophagy, acts as a scaffold protein, interacting with Atg9, Atg1 and other Atg proteins. Our research focuses on finding mutations in Atg11 that specifically disrupt its interaction with Atg9 without affecting its dimerization or interaction with Atg1. We targeted residues 455-535 of Atg11 as a putative Atg9 interaction site, performing mutagenesis on four key residues …

A Phytochemical Analysis Of Secondary Metabolites In Eupatorium Serotinum, Elise Snow

Theses and Dissertations

Phytochemistry, a subset of Natural Products Chemistry, studies chemically derived products from natural substances. Advances in this field have important applications in medicinal research due to the distinctive and unique properties of natural compounds. All metabolites are produced from the metabolic cycle, which is a pathway that provides energy for the organism. These metabolic compounds vary greatly and are classified based on their function within the organism. Primary metabolites are abundant and contribute to organism growth, development, and maintenance of energy. Secondary metabolites are found in lesser quantity and correlate to natural defense mechanisms. For example, salicylic acid is a …

Excited State Proton Transfer From Acidic Alcohols To A Quinoline Photobase Can Be Solvated By Non-Acidic Alcohol Solvents, Jonathan Ryan Hunt, Joseph Hecht, Clara Goolsby, Jade Hagihara, Monique Loza, Samantha Del Pozo

Chemistry and Biochemistry Faculty Works

Photobases are a type of molecule that become more basic upon photoexcitation and can therefore be used to control proton transfer reactions with light. The solvation requirements for excited state proton transfer (ESPT) in photobase systems is poorly understood, which limits their applicability. Here, we investigate the solvation of the ESPT reaction using 5-methoxyquinoline (MeOQ), a well-studied photobase with an excited state pKa (pKa*) of approximately 15.1, as a model system. Previous studies have shown that, in addition to the acidic donor that donates a proton to the photoexcited MeOQ, an additional “auxiliary donor” is necessary to solvate the resulting …

The Role Of Sugars In Aggregation Of The Protein Kassinin, Lillie G. Waldron

Student Summer Scholars Manuscripts

The aggregation of proteins to form amyloids is implicated in several diseases such as Alzheimer’s Disease, Parkinson’s Disease, and many others. This aggregation has several stages, progressing from isolated protein molecules (monomers) to small aggregates (oligomers), which are toxic to cells, and finally to large, string-like mature aggregates. Despite this association with disease, functional amyloids, which have normal biological functions, also result from protein aggregation. Kassinin, an amphibian peptide involved in nerve signal transmission, is a model system for functional amyloid study. To compare the aggregation of functional and disease-causing amyloids, we previously synthesized a fluorine-labeled kassinin through solid-phase peptide …

Emerging Chromatin Regulators In Response To Heavy Metal Exposure, Wesley Saintilnord

Theses and Dissertations--Molecular and Cellular Biochemistry

Environmental exposure to heavy metals poses significant threats to human health as they are associated with various developmental and chronic pathologies such as reproductive defects and cancers. Despite their profound risks, a comprehensive understanding of their disease-causing mechanisms is lacking. Most studies point to reactive oxygen species-induced DNA damage; however, their mutagenic potential is relatively weak suggesting the involvement of alternative mechanisms. One important, yet underexplored mechanism, is their ability to rewire the epigenome via DNA methylation and histone variant incorporation, leading to aberrant gene regulatory networks.

This study investigates the epigenetic mechanisms targeted by two ubiquitous heavy metals with …