Biochemistry, Biophysics, and Structural Biology Commons^™

Chemical Synthesis Of Sensitive Dna, Komal Chillar

Dissertations, Master's Theses and Master's Reports

Over the past decades, researchers have tried various chemical methods to synthesize modified oligodeoxynucleotides (ODNs, i.e. short segments of DNAs). Traditional ODN synthesis methods require strong basic, and nucleophilic conditions for the deprotection and cleavage of the ODN from the solid support. However, the sensitive ODNs containing labile functionalities are vulnerable to such harsh conditions. Sensitive ODNs have a wide range of applications in research and pharmaceuticals. To synthesize sensitive ODNs, researchers devised different strategies but no practical methods have been developed. To overcome these challenges, we developed alkyl Dim alkyl Dmoc technology. This innovative technology uses weakly basic and …

Under Ice Photosynthetic Primary Production And Dark Carbon Fixation In A Temperate Freshwater System, Vanessa Cubillos Tellez

Dissertations, Master's Theses and Master's Reports

Ice-covered lakes are vulnerable to environmental change, especially those in the Northern Hemisphere where ice cover is rapidly declining due to global warming. These changes can alter metabolic processes and disrupt carbon cycling driven by primary producers who form the base of the food chain and are key to sustaining ecosystem function. Photosynthetic primary production and dark carbon fixation under the ice in the Keweenaw Waterway, a temperate freshwater system that is ice-covered for ~3 months out of the year, were studied using a carbon isotopic labeling (14C-bicarbonate) technique. Water samples were collected weekly during ice cover and monthly during …

Multiscale Molecular Modeling Studies Of The Dynamics And Catalytic Mechanisms Of Iron(Ii)- And Zinc(Ii)-Dependent Metalloenzymes, Sodiq O. Waheed

Dissertations, Master's Theses and Master's Reports

Enzymes are biological systems that aid in specific biochemical reactions. They lower the reaction barrier, thus speeding up the reaction rate. A detailed knowledge of enzymes will not be achievable without computational modeling as it offers insight into atomistic details and catalytic species, which are crucial to designing enzyme-specific inhibitors and impossible to gain experimentally. This dissertation employs advanced multiscale computational approaches to study the dynamics and reaction mechanisms of non-heme Fe(II) and 2-oxoglutarate (2OG) dependent oxygenases, including AlkB, AlkBH2, TET2, and KDM4E, involved in DNA and histone demethylation. It also focuses on Zn(II) dependent matrix metalloproteinase-1 (MMP-1), which helps …

The Photo-Transformation Of Free Methionine In The Presence Of Surrogate And Standard Isolate Dissolved Organic Matter Under Sunlit Irradiation, Benjamin J. Mohrhardt

Dissertations, Master's Theses and Master's Reports

Sulfur (S)-containing amino acids are key sources of carbon, nitrogen, and sulfur involved in protein synthesis, protein function, and providing energy for microbial growth. Dissolved free and combined methionine is one of two S-containing amino acids incorporated into proteins and has been attributed to their stability and function. The oxidation of methionine has received considerable attention given its ubiquitous presence in most biological systems and has been associated with losses in protein function and pathological disorders. In natural waters, methionine is rapidly and selectively taken up by microorganisms to achieve cellular requirements of carbon, nitrogen, and sulfur. The abiotic transformation …

Investigation Of A Carbon Monoxide Dehydrogenase From An Uncultured Archaeon, Luke Moore

Dissertations, Master's Theses and Master's Reports

The Nickel based Carbon Monoxide Dehydrogenase (CODH) is an anaerobic metalloenzyme responsible for the reversible conversion of CO and water into CO2 and 2 protons and 2 electrons. This enzyme has importance in the environment as one of Earth’s first carbon fixation pathways, and for human uses as a potential source of biofuels and other commodity chemicals. CODH enzymes are present in a wide array of taxa, many of which are uncultured. In this study we express and purify the catalytic subunit (CooS) of the anaerobic CODH from an uncultured Hydrothermarchaeota JdFR-17 co-expressed with the nickel insertion accessory protein (CooC) …

Multilevel Computational Investigation Into The Dynamics And Reaction Mechanisms Of Non-Heme Iron And 2-Oxoglutarate Dependent Enzymes, Shobhit Sanjeev Chaturvedi

Dissertations, Master's Theses and Master's Reports

Computational chemistry methods have been extensively applied to investigate biological systems. This dissertation utilizes a multilevel computational approach to explore the dynamics and reaction mechanisms of two groups of enzymes belonging to non-heme Fe(II) and 2-oxoglutarate (2OG) dependent superfamily – histone lysine demethylases from class 7 and ethylene forming enzyme (EFE). Chapter 2 uncovers the role of conformational dynamics in the substrate selectivity of histone lysine demethylases 7A and 7B. The molecular dynamics (MD) simulations of the two enzymes revealed the importance of linker flexibility and dynamics in relative orientations of the reader (PHD) and the catalytic (JmjC) domains. Chapter …

Cancer And Quiescence: Investigating How The Dream Complex And Retinoblastoma Regulate The Cell Cycle, Lydia Rotman

Dissertations, Master's Theses and Master's Reports

An estimated 1.9 million people in the United States will be diagnosed with cancer in 2022. Cancer is characterized by uncontrolled cell growth, resulting from loss-of-function of key cell cycle regulatory proteins. The retinoblastoma protein (pRb) and p130, are two proteins that regulate cellular entry into the cell cycle. Both pRb and p130 repress expression of cell cycle genes, with pRb interacting with and suppressing E2F-DP transcriptional activators and p130 assembling in the DREAM transcriptional repressor complex. When normal cells receive signals to enter the cell cycle, cyclin and cyclin-dependent kinase (CDK) complexes phosphorylate pRb and p130, causing both to …

Auxin-Induced Degradation Of Dream Proteins, Lin-9 And Lin-54, In Caenorhabditis Elegans, Karli E. Chosa

Dissertations, Master's Theses and Master's Reports

The Dp, Retinoblastoma, E2F, And MuvB (DREAM) complex mediates transcriptional repression and is highly conserved throughout a number of species, including vertebrates, Drosophila melanogaster, and Caenorhabditis elegans. Differing from mammalian DREAM, C.elegans DRM, appears to act solely in a repressive role, with the MuvB subcomplex (LIN-9, LIN-37, LIN-52, LIN-53, and LIN-54) playing a key role in the repression of genes. In this study, we use the auxin-inducible degron (AID) system, an effective, fast-acting, tool used in the degradation of degron-tagged proteins to individually deplete two key proteins of the MuvB subcomplex, LIN-9 and LIN-54, in C. elegans. The …

Applications Of Machine Learning In Microbial Forensics, Ryan B. Ghannam

Dissertations, Master's Theses and Master's Reports

Microbial ecosystems are complex, with hundreds of members interacting with each other and the environment. The intricate and hidden behaviors underlying these interactions make research questions challenging – but can be better understood through machine learning. However, most machine learning that is used in microbiome work is a black box form of investigation, where accurate predictions can be made, but the inner logic behind what is driving prediction is hidden behind nontransparent layers of complexity.

Accordingly, the goal of this dissertation is to provide an interpretable and in-depth machine learning approach to investigate microbial biogeography and to use micro-organisms as …

Spatial And Temporal Comparison Of Persistent Organic Pollutants In The Boardman River, Collin Diedrich

Dissertations, Master's Theses and Master's Reports

Dam removal is a critical part of river and stream remediation projects around the world. Frequently dams are associated with impoundment ponds containing sediments that can act as a sink of various persistent organic pollutants (POPs) that can pose risks for human and aquatic wildlife. In this study, we deployed semi-permeable membrane devices (SPMDs) at multiple locations along a 25-mile stretch of the Boardman River in Traverse City Michigan to passively sample POP concentrations in this area that has recently undergone dam and impoundment pond sediment removal. Concentrations of polychlorinated biphenyl (PCB), di-chloro-diphenyl-trichloroethane (DDT) and cyclodiene compounds were in the …

Role Of Microrna-483 In Pancreatic Β-Cells, Jackson Waugh

Dissertations, Master's Theses and Master's Reports

Insulin is an essential hormone produced by β-cells in the pancreas. The release of insulin is tightly regulated in healthy people in order to control blood sugar level in our body. However, people with Type 2 Diabetes have insufficient insulin secretion from pancreatic β-cells, leaving to high blood sugar (hyperglycemia) and β-cell failure. microRNAs (miRNAs or miR) are newly discovered small regulatory molecules and have emerged as important regulator of cell growth, differentiation, and organ function. Altered miRNA function has been implicated in the pathogenesis of a variety of human disease, including diabetes. In this report, we focus on dissecting …

Exploring Substrate Specificity Of Fructose Transporters En Route To Glut Specific Probes For Biochemical And Biomedical Applications, Vagarshak Vigenovich Begoyan

Dissertations, Master's Theses and Master's Reports

Carbohydrate Transporters (GLUTs) are responsible for the transportation of sugars into the cell and have been of great interest in research for decades. Alterations or mutations that result in overexpression of GLUTs have been linked to a great number of diseases including, obesity, diabetes, and cancer. Differentiation between transporters has been shown to be incredibly difficult due to the highly conserved nature of the transporter structure, and thus specific targeting of transporters has proven a difficult challenge. Additionally, the GLUTs have been shown to high flexibility in their conformations, so it is difficult to determine what can or cannot pass …

Virus Purification Framework And Enhancement In Aqueous Two-Phase System, Pratik Umesh Joshi

Dissertations, Master's Theses and Master's Reports

Viral infections regularly pose detrimental health risks to humans. Preventing viral infections through global immunization requires the production of large doses of vaccines. The increasing demand for vaccines, especially during pandemics such as COVID-19, has challenged current manufacturing strategy to develop advanced unit operations with high throughput capability. Over the decade, the upstream processing responsible for synthesizing viral products in cell cultures has shown significant success in yielding high titers of viruses and virus-like particles. The progress in the upstream stage has now shifted the bottleneck to the downstream processing (DSP). Overlooked for decades, the DSP responsible for viral product …

The Impact Of Household Biocides And Antibiotics On Aquatic Microbial Community Composition, Abdulaziz Saud M Alrashdi

Dissertations, Master's Theses and Master's Reports

Triclosan (TCS) is antimicrobial agent that is used in a lot of consumer products, including toothpaste, liquid and bar soap, and cosmetics. TCS has been found in many lakes and rivers in the United States. However, The Food and Drug Administration (FDA) banned TCS recently and it will no longer be used in household products. Despite the recent ban, TCS is known to persist in the environment and may have long-term impacts. We conducted an experiment on using fresh water from three locations Houghton, Green Bay and the Huron Mountains. Our goals in the study is to assess the impact …

Near-Infrared Fluorescent Probes For Sensitive Determination Of Lysosomal & Mitochondrial Ph In Live Cells, Wafa Mazi

Dissertations, Master's Theses and Master's Reports

Varied intracellular pH levels are critical for various physiological processes such as enzymatic activity, cell proliferation and apoptosis, ion transport, and muscle contraction. Cellular compartments, like lysosomes, must retain an acidic environment (pH ~ 4.5) to activate hydrolytic enzymes necessary for the breakdown of large biomolecules. Another cellular organelle, the mitochondria, provides the cell with energy and must retain an alkalis environment (pH ~ 8.0) for proper function. Substantial lysosomal and mitochondrial pH deviation is associated with cellular dysfunction and disease. Therefore, the precise detection of lysosomal and mitochondrial pH is essential to provide a better understanding of cellular physiological …

Manipulation Of Genes Involved In Secondary Cell Wall Development During Wood Formation In Poplar, Kavitha Satish Kumar

Dissertations, Master's Theses and Master's Reports

Lignins are second most abundant components of vascular plant cell walls. They provide plants with structural rigidity and are polymers of monolignols. Lignin polymerization is catalyzed by peroxidases and/or laccases. These enzymes are suggested to share functional overlap and mechanism by which they coordinate this process is not clearly understood. There are about 100 peroxidases and 50 laccase genes known in poplar genome out of which some stem differentiating xylem-specific (SDX) enzymes were selected for our study. The main objective was to genetically manipulate genes expressed in the SDX region in the cell wall to see the effects on lignin …

The Abiotic Stress Response Of Hydroponic Vetiver Grass (Chrysopogon Zizanioides L.) To Acid Mine Drainage And Its Potential For Environmental Remediation, Jef Kiiskila

Dissertations, Master's Theses and Master's Reports

Mining activities can generate acid mine drainage (AMD), an acidic discharge that contains elevated sulfate (SO₄^2-), soluble metals, and orange-yellow metal-containing particulates. AMD imposes ecological risks from metal toxicity and physical stress, which may physically spread to nearby water sources or biologically through bioaccumulation. Current methods for AMD treatment, such as chemical or passive biological treatments, are often non-sustainable. Chemical treatments can be expensive and create large amounts of secondary waste, whereas biological treatments like anaerobic wetlands require continuous maintenance through input of organic nutrients. The end goal of this research is to develop a cost-efficient and …

Quantitative Genetics Of Populus, Roba Bdeir

Dissertations, Master's Theses and Master's Reports

Evidence for bark, stem and stomatal density adaptation to different climates in the model species Populus is seen in both the natural population as well as in the greenhouse, but the genetic basis of these adaptation remains poorly understood. The present thesis investigates bark texture, bark thickness, diameter and stomatal density variations among Populus population using two quantitative genetics methods to attempt understand the genetic system controlling inheritance of these traits and to associate them with respective genes. The first approach aimed at detecting quantitative trait loci (QTL) associated with all phenotypic traits in an interspecific hybrid pedigree (Populus …

A Journey Towards Understanding Biology Holistically At The Nanoscale, Trevor Moser

Dissertations, Master's Theses and Master's Reports

Characterizing biological processes with microscopy techniques that allow one to directly visualize the complexity of life is an important component of understanding both physiological function and structure. The wide spectrum of biological structures from individual proteins to whole ecosystems necessitates that multiple techniques are used to characterize all levels of organization. While existing techniques cover portions of this spectrum, continued improvement of established methods and development of new techniques is needed. This dissertation outlines my journey in enabling new approaches for imaging biosystems at various scales. Chapters 1 and 2 provide motivation for bioimaging and background for the use of …

Portulaca Oleracea Extract Can Inhibit Nodule Formation Of Colon Cancer Stem Cells By Regulating Gene Expression Of Notch Signal Transduction Pathway, Li Chen

Dissertations, Master's Theses and Master's Reports

The main aim of this study was to investigate the effects of Portulaca oleracea extract on tumor formation in colon cancer stem cells and chemotherapy sensitivity. In addition, this study analyzed the genetic changes within the Notch signal transduction pathway associated with the effects of the extracts. Serum-free cultures of colon cancer cells (HT-29) and HT-29 stem cells were treated with the chemotherapeutic drug 5-FU to assess sensitivity. Injections of the stem cells were also given to BALB/c mice to confirm tumor growth and characteristics. In addition, the effect of different concentrations of P. oleracea extract was tested on the …

Heterologous Expression And Purification Of Full-Length Human Polybromo-1 Protein, Sarah Hopson

Dissertations, Master's Theses and Master's Reports

Over the past decade, it has become apparent that the human polybromo-1 protein (BAF180) has a critical role in cancer. BAF180 is known to be a driver mutation in clear cell renal cell carcinoma, where it has been found to be mutated in approximately 40% of cases. Mutations have also been found in several other cancers, including intrahepatic cholangiocarcinomas and epithelioid sarcomas. BAF180 is the chromatin targeting subunit of the PBAF (Polybromo-associated BRG1-associated factor) chromatin remodeling complex, a role facilitated by its nine domains: six bromodomains, which recognize and bind to acetylated lysines on histones; two BAH (bromo-adjacent homology) domains, …

Methane Fluxes And Porewater Dissolved Organic Carbon Dynamics From Different Peatlands Types In The Pastaza-Marañon Basin Of The Peruvian Amazon., Jhon Del Aguila-Pasquel

Dissertations, Master's Theses and Master's Reports

Relevant components of the carbon budget such as methane fluxes and porewater dissolved organic carbon (DOC) are poorly characterized in the Peruvian Pastaza Marañon basin (PMB). PMB is associated with a tropospheric hotspot for methane and therefore it may represent a significant methane source. We aimed to quantify the magnitude of CH₄ fluxes and porewater DOC; and to determine their predictors across different peatland types in the PMB (open peatland, palm swamp, and pole forest). The study was conducted in two peatland sites covering the three main vegetation types in PMB. We collected gas and water samples using chamber-based …

The Effect Of Posttranslational Modifications On Protein Aggregation, Morphology, And Toxicity, Mu Yang

Dissertations, Master's Theses and Master's Reports

Proteins are one of the most versatile macromolecules in the biological system. The function or activity of a protein highly depends on its 3D native structure. However, under stress, they are at risk of misfolding/aggregation, leading to formation of structures that can indicate loss of function or gain of toxicity. In severe cases, protein aggregation can result in many diseases, including neurodegenerative diseases, such as Alzheimer’s, Parkinson’s, Huntington’s, and amyotrophic lateral sclerosis. Due to the heterogeneous nature of cellular environment and protein molecules, mechanism of in vivo folding and related toxicity still remains elusive. To have a better understanding of …

Effect Of Disulfide Bond Scrambling On Protein Stability, Aggregation, And Cytotoxicity, Colina Dutta

Dissertations, Master's Theses and Master's Reports

Proteins are nano-machines that carry out majority of the cellular functions. Thermodynamically they are functional and stable within a very narrow range (1 kcal/mol). External perturbations in the form of pH change, thermal, or oxidative/reducing stress can destabilize the protein resulting in misfolding and aggregation. Prolonged environmental stress can affect the cells adaptive response resulting in loss of ability to refold or recycle proteins. This can lead to accumulation of misfolded or aggregated proteins within the cell. Such accumulation of aggregated proteins have been associated with neurodegenerative disorders such as Amyotrophic Lateral Sclerosis (ALS), Parkinson’s, Huntington’s, and Alzheimer’s disease. There …

Sensing And Mapping Of Surface Hydrophobicity Of Proteins By Fluorescent Probes, Nethaniah Dorh

Dissertations, Master's Theses and Master's Reports

Surface hydrophobic interactions in proteins play a critical role in molecular recognition, influence biological functions, and play a central role in many protein misfolding diseases. As significance of surface hydrophobic interactions in age-related proteinopathies is becoming clear; it has led to an increased demand for better probes and tools to sense and characterize protein surface hydrophobicity. Current commercially available fluorescent probes such as 8-anilino-1-naphthalene sulfonic acid (ANS), 4,4′ -dianilino-1,1′-binaphthyl-5,5′-disulfonic acid (Bis-ANS), 6-propionyl-2-(N,N-dimethylamino)naphthalene (PRODAN), tetraphenylethene derivative, and Nile Red can sense proteins average hydrophobicity. However, probe limitations prevents their application for measuring the protein surface hydrophobicity. Some of the major deficiencies …

Systematic Study Of The Biological Effects Of Nitric Oxide (No) Using Innovative No Measurement And Delivery Systems, Weilue He

Dissertations, Master's Theses and Master's Reports

Nitric oxide (NO) is recognized as the most important small signaling molecule in the human body. An imbalance of NO is closely associated with many serious diseases such as neurological disorders, cardiovascular diseases, chronic inflammations and cancers. Herein two chemiluminescence-based devices (a real-time NO measurement device and a controllable NO delivery device) were developed to facilitate the NO quantitative study and obtain information for NO related drug design.

The first device used for real-time measuring NO(g) flux from living cells was developed and validated. The principle was to use a two-chamber design, with a cell culture chamber and a gaseous …