Medicinal and Pharmaceutical Chemistry Commons^™

Structure-Based Drug Discovery And Development Of Protein Structure Prediction Tools Using An Empirical Force Field, Noah B. Herrington

Theses and Dissertations

Traditional drug discovery has rapidly accelerated thanks to development of computational molecular modeling. The crucial component that these computational studies hinge upon is having a well-defined, and energetically favorable structure. Structures of proteins and ligands that meet these criteria are important for accurately simulating models used to study drug binding. To demonstrate the role of accurate structure simulation in the study of these events, this thesis presents, first, a story examining the problem of accurate structure modeling of ionizable residues within protein structures, specifically aspartic acid, glutamic acid, and histidine. I present our method, which uses the HINT force field …

Protein Structure And Interaction: The Role Of Aromatic Residues In Protein Structure And Interactions Between Pyridoxine 5'-Phosphate Oxidase/Dopa Decarboxylase, Mohammed H. Al Mughram

Theses and Dissertations

Naturally developed proteins are capable of carrying out a wide variety of molecular functions due to their highly precise three-dimensional structures, which are determined by their genetically encoded sequences of amino acids. A thorough knowledge of protein structures and interactions at the atomic level will enable researchers to get a deep foundational understanding of the molecular interactions and enzymatic processes required for cells, resulting in more effective therapeutic interventions. This dissertation intends to use structural knowledge from solved protein structures for two distinct objectives.

In the first project, we conducted a bioinformatics structural analysis of experimental protein structures using our …

Studies Toward The Development Of An Improved Countermeasure For Synthetic Opioid Overdose, Sidnee L. Hedrick

Theses and Dissertations--Pharmacy

One of the most prominent opioid analgesics in the United States is the high potency agonist fentanyl. It is used in the treatment of acute and chronic pain and as an anesthetic adjuvant. When used inappropriately, however, ingestion of just a few milligrams of fentanyl or other synthetic opioid can cause opioid-induced respiratory depression (OIRD), often leading to death. Currently, the treatment of choice for OIRD is the opioid receptor antagonist naloxone. Recent reports, however, suggest that higher doses or repeated dosing of naloxone (due to recurrence of respiratory depression) may be required to fully reverse fentanyl-induced respiratory depression, rendering …

Development Of Accurate And Efficient Computational Methodologies For Predicting Protein-Ligand And Protein-Protein Binding Free Energies, Alexander Hamilton Williams

Theses and Dissertations--Pharmacy

Computational modeling is an invaluable tool in the drug discovery process either for small ligand or protein therapeutics. The widespread availability of protein X-Ray Crystal and Cryo-Electron Microscopy (Cryo-EM) structures has allowed for more accurate molecular dynamics (MD) simulations that are not reliant on methods such as homology modeling, which may produce structures that require significant computational time to demonstrate their stability. In this thesis we describe several novel methodologies for the computationally efficient modeling of protein/ligand and protein/protein complexes that may be employed within both large-scale virtual screenings and lead compound optimization. These methodologies may also be utilized in …

Examining Ayahuasca Constituents At 5-Ht2a Receptors In Search Of Antidepressant Action, Jeremy D. Rolquin

Theses and Dissertations

Recently, it has been reported that ligands of the 5-HT_2A receptor can have drastic and fast-acting efficacy towards a number of different mental health disorders, such as depression and anxiety. A mixture of Amazonian plants calledayahuasca contains multiple compounds which have been shown to interact with the serotonergic system, and the 5-HT_2Areceptor in particular.

The structurally similar compounds (DMT, harmine, harmaline, and tetrahydroharmine) found in ayahuasca were examined for differences in their physiochemical properties that might contribute to their binding affinity for the 5-HT_2Areceptor. 3D Molecular modeling and docking studies of these compounds were …

The Vagabond Flourine Atom Revisited: Dissociative Photoionization Of Tri- And Pentafluoropropene, Jessica K. De La Cruz

University of the Pacific Theses and Dissertations

Photoelectron Photoion Coincidence (PEPICO) Spectroscopy studies on two unsaturated hydrofluorocarbons (HFCs), also known as hydrofluoroolefines (HFOs), are presented here. Previously, the Sztáray group has studied the dissociation of trans-1,3,3,3-tetrafluoroprop-1-ene (ElixClean), which is a fourth-generation refrigerant and propellant and has lower global warming potential than its precursors. My study is an extension of the ElixClean study as it aims to explore how the different number of fluorine atoms impact the dissociation reactions of these molecules. Both 3,3,3-trifluoropropene (TFP) and cis-1,2,3,3,3- pentafluoropropene (PFP) are also utilized as propellants and refrigerants.Measurements were carried out with remote access to the CRF-PEPICO (combustion reactions followed …

Gc/Ms And Lc/Ms Approaches To Chemical Communication In Plants And Marine Cyanobacteria, Carolyn Keim

University of the Pacific Theses and Dissertations

Natural products are small organic compounds synthesized by living organisms including plants, animals, and microbes. These fall into one of two categories, primary metabolites are required for survival, but secondary metabolites usually play a more accessory role. Extracts from organisms have proven to be useful to humans throughout history. Prior to evidence-based western medicine practices, natural products were the only source of medicine and remain as a treatment source for underdeveloped nations. Today, natural products have either been approved by or have served as the template for many FDA approved drugs. Based on a survey of all FDA approved drugs …

Investigation Of Cdk8 Inhibitor Q-12 Effects On Cdk8 And Cdk8 Substrates In Triple Negative Breast Cancer Cell Line Mda-Mb-468, Shengxi Li

University of the Pacific Theses and Dissertations

Cyclin-dependent kinases (CDKs) and cyclins (Cyclins) are the core molecules in the regulation mechanism of the entire cell cycle. Cell cycle dysregulation is a common feature of human cancers, and inhibitors of cyclin-dependent kinases (CDKs) play a crucial role in cell cycle control and are one of the most promising areas of cancer therapy. We aspired to use our cyclin-dependent kinase 8 (CDK8) 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 (TNBC) and colorectal cancer cell lines …

Optimization Of The Structure Of Ttr Ligands For Half-Life Extension (Tlhe), Guanming Jiang

University of the Pacific Theses and Dissertations

Many potential therapeutic agents face challenges for their clinical development due to short circulation half-life. As a result, prolonging the half-life of therapeutic drugs in circulation while preserving their hydrophilicity and small size will be a key step toward more effective and safe pharmacological molecules. Our lab developed a new approach for enhancing the safety and efficacy of therapeutic agents. By endowing therapeutic agents with a hydrophilic small molecule (a derivative of the clinical candidate, AG10) which reversibly binds to the serum protein transthyretin (TTR), the half-life of the therapeutic agent should be extended by binding to the TTR in …

Expression Of Mouse Full-Length Aryl Hydrocarbon Receptor And Human Aryl Hydrocarbon Receptor Ligand Binding Domain In Pichia Pastoris, Yiyuan Wang

University of the Pacific Theses and Dissertations

Aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor that regulates biological responses to planar aromatic hydrocarbon. AHR activates gene transcription by binding to its corresponding enhancer with its partner-aryl hydrocarbon receptor nuclear translocator (ARNT). In addition, this receptor has been shown to regulate xenobiotic-metabolizing enzymes such as cytochrome P450. AHR exists widely in body tissues and affects bioactivation of carcinogenic compounds, T cell differentiation, fatty acid synthesis, cell proliferation, hematopoietic stem cell differentiation, respiratory reactivity, and insulin sensitivity. Although the precise mechanism illustrating the endogenous AHR function remains unclear, there has been intense interest in exploring AHR as a …

Peripherally Restricted Delivery System Provides Insights On The Role Of Cns In Precipitating Opioid-Induced Constipation, Dengpan Liang

University of the Pacific Theses and Dissertations

A serious opioid crisis is affecting public health and economics, eroding people’s quality of life. 80% of patients who receive opioids suffer from adverse effects such as Opioid-induced constipation (OIC). However, there is no efficient medicine for these adverse effects. Notably, mainstream theory supports that analgesia effects are mainly controlled by CNS while OIC is predominately controlled by peripheral. In addition, the sites of action of opioid was based on the assumption that mu-opioid receptor antagonists (PAMORAs), did not cross the blood-brain barrier (BBB). Unfortunately, the BBB crossing of PAMORAs mislead the understanding of the role of the central nervous …

Thermodynamic Mechanisms Of Helix Stabilization In A Model Peptide And Protein, Ryan Murray

University of the Pacific Theses and Dissertations

Biologics are large, complex therapeutic agents generally produced from living organisms. One group of biologics is peptide/protein based. Biological agents offer unique advantages over traditional therapeutics including longer half-lives, higher specificity, greater efficacy, and reduced off-target effects. However, protein/peptide based drugs suffer from both delivery and stability issues. The higher order of protein structures (secondary, tertiary, etc.) derive ~80% of their conformational stability from paltry hydrophobic effects, with net stabilization of 5-15 kcal/mole observed for many proteins. Loss of conformational stability can lead to increased aggregation, precipitation, and degradation; and reduced activity and side effects. To increase stability and improve …

Incorporating Glutamic Acid-Valine-Citrulline Linker In Trifunctional Molecules Targeting Psma Ensures Enhanced Stability, Safety, And Efficacy In Mouse Model Of Prostate Cancer, Toufiq Ul Amin

University of the Pacific Theses and Dissertations

This project describes the development of a new antitumor therapeutic platform that combines the benefits of small-molecule drug conjugates (SMDCs) and antibody drug conjugates (ADCs). Valine-citrulline (VCit) dipeptide linkers are popular cathepsin B cleavable ADC linkers. Due to its instability in mouse serum, translating efficacy data from mouse to human is more difficult. It has been reported that replacing the VCit linker with glutamic acid-valine-citrulline (EVCit) improves ADC stability in mouse serum. The effect of the EVCit linker on the stability of SMDCs has not been reported so far. In a xenograft mouse model of prostate cancer, we found that …

Modified Ysk12-Mend-Sirna In Dendritic Cells For Cancer Immunotherapy, Syed S. Alam

Undergraduate Research Posters

Tumors may induce tolerogenesis through signaling dendritic cells to produce tolerogenic molecules, such as indoleamine 2, 3-dioxygenase 1 (IDO1). Tumor-associated immunosuppression is associated with higher mortality in patients. Small interfering RNA (siRNA) has been shown to silence specific target genes in the target cell. The siRNA associated with these genes could support a gene knockdown of these immunosuppressors and reduce mortality. Delivery of these therapeutic nucleic acids is difficult in vivo because siRNA is easily broken down inside the cell and the bloodstream through present nucleases. Use of liposome polymers has been reviewed extensively in literature. YSK12-C4, a lipid nanoparticle …