Life Sciences 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 …

Pharmacogenomics And Ssris Appropriateness In Older Community Dwelling African Americans, Wint War Phyo, Lana Sargent, Elvin T. Price

Graduate Research Posters

Background: Depressive and anxiety disorders are among the most common illnesses experienced by older adults (age > 60). The selective serotonin reuptake inhibitors (SSRIs) are preferred class of antidepressants for these disorders due to their high efficacy and safety profiles among older adults. However, SSRIs are metabolized by highly polymorphic cytochrome P450 enzymes, specifically CYP2D6 and CYP2C19. This can lead to variable dose-response outcomes, especially among older African American population.

Objective: Analyze the frequency of CYP2D6 and CYP2C19 polymorphisms in African American older adults who are taking SSRIs and identify potential inappropriate use of SSRIs in these older adults using the …

Investigating Cannabinoid Type-1 Receptor (Cb1r) Positive Allosteric Modulators (Pams) In Mouse Models Of Overt Cannabimimetic Activity, Subjective Drug Effects, And Neuropathic Pain, Jayden Elmer

Theses and Dissertations

Chronic pain affects between 20 and 30 percent of the adult population in western countries and represents a wide array of specific etiologies (Berge, 2011). Neuropathic pain secondary to traumatic nerve injury, chemotherapeutic toxicity, or diseases (e.g., diabetes mellitus) is often refractory to conventional analgesics, with patients receiving less than 50% pain relief compared to placebo (Finnerup et al. 2010). The endocannabinoid system has shown potential as a therapeutic target for neuropathic pain wherein CB1 agonism via administration of exogenous agonists or pharmacological blockade of endocannabinoid catabolic enzymes exhibits efficacy in reversing allodynia in the chronic constriction injury (CCI) model …

Nebulizer-Based Systems To Improve Pharmaceutical Aerosol Delivery To The Lungs, Benjamin M. Spence

Theses and Dissertations

Combining vibrating mesh nebulizers with additional new technologies leads to substantial improvements in pharmaceutical aerosol delivery to the lungs across therapeutic administration methods. In this dissertation, streamlined components, aerosol administration synchronization, and/or Excipient Enhanced Growth (EEG) technologies were utilized to develop and test several novel devices and aerosol delivery systems. The first focus of this work was to improve the poor delivery efficiency, e.g., 3.6% of nominal dose (Dugernier et al. 2017), of aerosolized medication administration to adult human subjects concurrent with high flow nasal cannula (HFNC) therapy, a form of continuous-flow non-invasive ventilation (NIV). The developed Low-Volume Mixer-Heater (LVMH) …

Model-Based In-Vitro Pk/Pd Profiling Of Novel Synthetic Allosteric Effectors Of Hemoglobin (Aeh) As Potential Sickle Cell Disease (Scd) Therapeutics, Xiaomeng Xu

Theses and Dissertations

Introduction: Allosteric effectors of hemoglobin (AEH) represent a class of synthetic aromatic aldehydes that transiently form covalent interactions (Schiff-base) with hemoglobin (Hb) to form Hb-AEH adduct, preventing the HbS polymerization and sickling of red blood cells (RBC). The overall objective of this research was to aid in the optimization of novel AEH by understanding their target-site disposition of AEH in relevant biological matrices, e.g., HbA solution, whole blood (WB) and human liver cytosol (HLC), a surrogate of aldehyde dehydrogenase (ALDH)-mediated oxidative metabolism.

Methods: A “universal” HPLC-UV/Vis assay method was developed for the quantitation of HbA-AEH adduct for chemically …

Ndrg1 And Myelin-Related Disease: Alcoholism And Chemotherapy-Induced Neuropathy, Guy Harris

Theses and Dissertations

Alcohol use disorder (AUD) is a prevalent neuropsychiatric disease with profound health, social, and economic consequences. With an estimated 50% heritability, identifying genes that engender risk and contribute to the underlying neurobiological mechanisms represents an important first step in developing effective treatments. Gene expression studies are an important source of candidate genes for studying AUD, providing windows into the molecular machinery engaged by the brain in response to ethanol. Our laboratory has implicated N-myc down-regulated gene 1 (Ndrg1) as a potential candidate gene that modulates ethanol-induced changes in myelin-related gene expression and acute sensitivity to ethanol. Analysis of …

Development Of A Screening Assay For Type Iii Secretion System Inhibitors And High Throughput Screening Campaign Of Inhibitors Of Prp Of Staphylococcus Aureus, Heather A. Pendergrass

Theses and Dissertations

Antibiotics inhibit the growth or survival of bacteria by targeting their essential functions.¹ Due to weaknesses in traditional antibiotics and the increasing prevalence of antibiotic resistance genes, virulence factors are being targeted for therapeutic treatment of bacterial infection.² We have developed an assay to quantify and observe type III secretion system (T3SS) activity. The type III secretion system (T3SS) is a virulence factor present in some Gram-negative pathogens including enteropathogenic and enterohemorrhagic E. coli (EPEC and EHEC, respectively),³ and others.^4–9 The T3SS between EPEC and EHEC are highly conserved and share over 90% sequence identity with …

Epigenetic Regulation Of Drug Metabolizing Enzymes In Normal Aging, Mohamad M. Kronfol

Theses and Dissertations

Geriatric populations are at a higher risk for adverse drug reactions (ADRs). This may be partly due to changes in drug metabolism in old age, but the underlying mechanisms are poorly understood. Prior research in humans and mice has shown age-associated changes to the expression of several genes involved in drug metabolism. Furthermore, studies of human blood showed that epigenetic regulation of genes encoding drug metabolizing enzymes change with age. However, it is unknown if genes in the liver are similarly affected. Therefore, we hypothesize that genes encoding drug metabolizing enzymes may show differential epigenetic regulation in the liver with …

Design, Synthesis And Pharmacological Characterization Of Potential Mu Opioid Receptor Selective Ligands, Abhishek S. Kulkarni

Theses and Dissertations

Selective Mu Opioid Receptor (MOR) antagonists possess immense potential in the treatment of opioid abuse/addiction. Utilizing the “message-address” concept, our laboratory reported a novel, reversible, non-peptide MOR selective antagonist 17-cyclopropylmethyl-3,14β-dihydroxy-4,5α-epoxy-6β-[(4՛-pyridyl)carboxamido]morphinan (NAP). Molecular modeling studies revealed that the selectivity of NAP for the MOR is because of a π-π stacking interaction of its pyridine ring with the Trp318residue in theMOR. Pharmacological characterization showed that NAP is a P-glycoprotein substrate, thereby limiting its use in the treatment of opioid abuse/addiction. Thus, to modify NAP, we replaced the pyridine ring with its isosteric counterpart thiophene. Isosteric replacement …

Structure-Activity Relationship Studies Of Synthetic Cathinones And Related Agents, Rachel A. Davies

Theses and Dissertations

Synthetic cathinones and related agents represent an international drug abuse problem, and at the same time an important class of clinically useful compounds. Structure-activity relationship studies are needed to elucidate molecular features underlying the pharmacology of these agents. Illicit methcathinone (i.e., MCAT), the prototype of the synthetic cathinone class, exists as a racemic mixture. Though the differences in potency and target selectivity between the positional and optical isomers of synthetic cathinones and related agents have been demonstrated to have important implications for abuse and therapeutic potential, the two MCAT isomers have never been directly compared at their molecular targets: the …

Polygenic Scores For Metabolic Traits And Related Drug Prescriptions In The Michigan Genomics Initiative, Samuel K. Handelman, Xiaomeng Du, Yanhua H. Chen, Elizabeth K. Speliotes

Biology and Medicine Through Mathematics Conference

No abstract provided.

Modeling Pharmaceutical Inhibition Of Glucose-Stimulated Renin-Angiotensin System In Kidneys, Ashlee N. Ford Versypt, Minu R. Pilvankar, Hui Ling Yong

Biology and Medicine Through Mathematics Conference

No abstract provided.

Galantamine's Deconstruction In The Quest Of A Pam Pharmacophore, Malaika Argade

Theses and Dissertations

Alzheimer’s disease is a progressive neurodegenerative disorder generally affecting people above the age of 65 years. Even though the pathophysiological hallmarks of AD were established more than a hundred years ago, there is yet to be a drug that can stop its characteristic neuronal damage. Of the five currently FDA-approved drugs, galantamine has a unique mechanism of action. Apart from being an AChE inhibitor, galantamine can effectively potentiate (positive allosteric modulator) the effect of agonists at nAChRs at concentrations lower than those required for its action as an AChE inhibitor. Perhaps the clinical benefits observed with galantamine are associated mainly …

Study Of Molecular Interactions Of Glycosaminoglycans And Glycosaminoglycan Mimetics With Their Protein Targets, Daniel K. Afosah

Theses and Dissertations

Glycosaminoglycans (GAGs) are complex linear chain carbohydrate molecules found on virtually all animal cell surfaces. Owing to their negatively charged nature, GAGs interact with a number of different proteins. Thus, although they have great potential as therapeutic agents, their apparent promiscuous interactions increase their side effect risk. GAG mimetics, including GAG oligosaccharides and non-saccharide GAG mimetics (NSGMs) are viable approaches to address this. This work discusses sulfated benzofuran thrombin inhibitors with submaximal protease inhibition, sulfated diflavonoid inhibitors of plasmin and GAG oligosaccharides with selectivity for human neutrophil elastase (HNE).

Anticoagulants are very important for the treatment of thrombotic diseases. The …

Probing Allosteric, Partial Inhibition Of Thrombin Using Novel Anticoagulants, Stephen S. Verespy Iii

Theses and Dissertations

Thrombin is the key protease that regulates hemostasis; the delicate balance between procoagulation and anticoagulation of blood. In clotting disorders, like deep vein thrombosis or pulmonary embolism, procoagulation is up-regulated, but propagation of clotting can be inhibited with drugs targeting the proteases involved, like thrombin. Such drugs however, have serious side effects (e.g., excessive bleeding) and some require monitoring during the course of treatment. The reason for these side effects is the mechanism by which the drugs’ act. The two major mechanisms are direct orthosteric and indirect allosteric inhibition, which will completely abolish the protease’s activity. Herein we sought an …

Elaboration And Design Of Α7 Nachr Negative Allosteric Modulators, Osama I. Alwassil

Theses and Dissertations

α7 Neuronal nicotinic acetylcholine receptors are one of two major classes of receptors responsible for cholinergic neurotransmission in the central nervous system. The existence of α7 neuronal nAChRs in different regions of the nervous system suggests their involvement in certain essential physiological functions as well as in disorders such as Alzheimer’s disease (AD), drug dependence, and depression. This project was aimed toward the discovery and development of small–molecule arylguanidines that modulate α7 nAChR function with improved subtype-selectivity through an allosteric approach. Identifying the required structural features of these small molecules allowed optimization of their negative allosteric modulator (NAM) actions at …