Biochemistry Commons^™

Kinetic Mechanism Of Indigo-Producing Indole Monooxygenase From Acinetobacter Baumannii, Kanyarat Suksomjaisaman

Chulalongkorn University Theses and Dissertations (Chula ETD)

Indole, a bicyclic compound comprising a fused benzene and pyrrole ring, serves as a fundamental component in numerous natural compounds. Additionally, indole holds significant importance in industrial applications, particularly in the production of pharmaceutical drugs and agrochemicals. Flavin-dependent indole monooxygenase is an enzyme responsible for hydroxylation of the indole ring. Indole monooxygenase is a two-components: flavoprotein reductase containing FAD as a cofactor, and monooxygenase. The reductase component utilizes NADH to catalyze flavin reduction and transfers the reduced flavin to the monooxygenase component. The hydroxylation of indole by monooxygenase reduced FAD and oxygen as substrates. In this study, we cloned the …

Microbial Labilization And Diversification Of Pyrogenic Dissolved Organic Matter, Aleksandar I. Goranov, Andrew S. Wozniak, Kyle W. Bostick, Andrew R. Zimmerman, Siddhartha Mitra, Patrick G. Hatcher

Chemistry & Biochemistry Faculty Publications

With the increased occurrence of wildfires around the world, interest in the chemistry of pyrogenic organic matter (pyOM) and its fate in the environment has increased. Upon leaching from soils by rain events, significant amounts of dissolved pyOM (pyDOM) enter the aquatic environment and interact with microbial communities that are essential for cycling organic matter within the different biogeochemical cycles. To evaluate the biodegradability of pyDOM, aqueous extracts of laboratory-produced biochars were incubated with soil microbes, and the molecular changes to the composition of pyDOM were probed using ultrahigh-resolution mass spectrometry (Fourier transform–ion cyclotron resonance–mass spectrometry). Given that solar irradiation …

Copper(Ii) And Silver(I)‑1,10‑Phenanthroline‑5,6‑Dione Complexes Interact With Double‑Stranded Dna: Further Evidence Of Their Apparent Multi‑Modal Activity Towards Pseudomonas Aeruginosa, Anna Clara Milesi Galdino, Lívia Viganor, Matheus Mendonça Pereira, Michael Devereux, Malachy Mccann, Marta Helena Branquinha, Zara Molphy, Sinéad O'Carroll, Conor Bain, Georgia Menounou, Andrew Kellett, André Luis Souza Dos Santos

Articles

Tackling microbial resistance requires continuous efforts for the development of new molecules with novel mechanisms of action and potent antimicrobial activity. Our group has previously identified metal-based compounds, [Ag(1,10-phenanthroline-5,6-dione)2]ClO4 (Ag-phendione) and [Cu(1,10-phenanthroline-5,6-dione)3](ClO4)2.4H2O (Cu-phendione), with efficient antimicrobial action against multidrug-resistant species. Herein, we investigated the ability of Ag-phendione and Cu-phendione to bind with double-stranded DNA using a combination of in silico and in vitro approaches. Molecular docking revealed that both phendione derivatives can interact with the DNA by hydrogen bonding, hydrophobic and electrostatic interactions. Cu-phendione exhibited the highest binding affinity to either major (− 7.9 kcal/mol) or minor (− 7.2 kcal/mol) …

Structure Of A Monomeric Photosystem Ii Core Complex From A Cyanobacterium Acclimated To Far-Red Light Reveals The Functions Of Chlorophylls D And F, Christopher J. Gisriel, Gaozhong Shen, Ming-Yang Ho, Vasily Kurashov, David A. Flesher

Faculty Publications

Far-red light (FRL) photoacclimation in cyanobacteria provides a selective growth advantage for some terrestrial cyanobacteria by expanding the range of photosynthetically active radiation to include far-red/near-infrared light (700-800 nm). During this photoacclimation process, photosystem II (PSII), the water:plastoquinone photooxidoreductase involved in oxygenic photosynthesis, is modified. The resulting FRL-PSII is comprised of FRL-specific core subunits and binds chlorophyll (Chl) d and Chl f molecules in place of several of the Chl a molecules found when cells are grown in visible light. These new Chls effectively lower the energy canonically thought to define the "red limit" for light required to drive photochemical …

Understanding The Impact Of Human Germline Single-Nucleotide Variants, Samuel Adjei

Electronic Theses and Dissertations

All genetic variations in the human genome are due to mutations, and therefore determining the impact of the different categories of mutations, particularly nonsynonymous single nucleotide variants (SNVs) which are the most abundant in the population is essential for understanding the genetics of human diseases. Generations of mutation studies have focused on a relatively small number, partly due to technological limitations. However, advances in next-generation sequencing have allowed for empirical assessments of genome-wide mutations. genome sequence of any individual contains extensive protein-altering genetic variation (missense mutations) and of which only a few are unambiguously deleterious. Characterizing the phenotypes of these …

Synthesis Of Oligonucleotides Containing Unnatural Backbone And Regulation Of Crispr Activity Using Inverse Electron Demand Diels-Alder Chemistry, Alyssa Hoy

Legacy Theses & Dissertations (2009 - 2024)

This thesis describes the synthesis of an oligonucleotide containing an unnatural neutralbackbone. The backbone was constructed using bio-orthogonal inverse electron demand Diels- Alder chemistry between trans-cyclooctene (TCO) and tetrazine (Tz). A TCO phosphoramidite was synthesized and attached to solid support for strand propagation. Uridine monomers containing either bis-TCO or bis-Tz were also synthesized. The oligonucleotide strand was formed by sequential ligation of the bis-Tz and bis-TCO monomers. The oligonucleotide was analyzed using mass spectrometry. This thesis also describes the synthesis of sgRNAs containing non-canonical nucleobases, m1A, m6A, s2U and s4U using the ‘split-and-click’ methodology. The synthetic sgRNAs were assembled using …

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 …

Identification And Characterization Of Transcription Factors Regulating Methionine Gamma-Lyase Gene Expressionin Durian Durio Zibethinus M. Pulps, Pinnapat Pinsorn

Chulalongkorn University Theses and Dissertations (Chula ETD)

Durian (Durio zibethinus L.) is an economic fruit crop in Southeast Asia. In Thailand, more than 200 durian varieties are found. Among them, two commercial cultivars which are Chanee and Monthong are mainly cultivated. Durian fruit releases a strong sulfuryl odor containing ethanethiol, methanethiol, and hydrogen sulfide during ripening. Methionine γ-lyase (MGL) is an enzyme responsible for α, γ-elimination of L-methionine into methanethiol, ammonia, and α-ketobutyrate. MGL gene is highly expressed in durian pulps during ripening concurring with methanethiol production during ripening. However, the function of durian MGL (DzMGL) has not been characterized. Thus, the enzymatic activity assay towards L-methionine, …

Identification Of Glutathionylated Cysteines Regulating Cell Migration, Dhanushika Kukulage

Wayne State University Dissertations

Cell migration is vital in many physiological processes, such as wound repair and metastasis. Impaired cell migration in wound healing may result in chronic wounds, by which 6.7 million Americans are affected, and they suffer from bacterial infections, amputations, increased mortality, and depression. Reactive oxygen species (ROS) or hydrogen peroxide (H2O2) play an essential role as a second messenger in redox signaling. Evidence has been found that H2O2 takes part in regulating cell migration as well. A primary mechanism of ROS regulating redox signaling is oxidative protein modifications. Protein S-glutathionylation, one of the oxidative modifications, is the conjugation of glutathione …

Effect Of Allosteric Site Binding On Smyd2 Conformational Ensemble, Jacob Daniel Sobota

Wayne State University Theses

Molecular dynamics simulation allows for the simulation of proteins with precise control over what ligands are present at what sites. The conformational ensemble of a protein can be obtained from MD simulation with and without binding at an allosteric site and compared between to gain insight at what effects binding at an allosteric site has on a protein’s structure. SMYD2, a critical regulator of cellular processes, was recently found to have a novel secondary binding site with allosteric effects on its activity. The discovery of an allosteric site has implications for drug design in the inhibition of SMYD2 to treat …

Mhc Diversity Analysis Of Spheniscus Demersus For In Situ And Ex Situ Populations, Antonieta Van Den Berg Monsalve

Undergraduate Honors Thesis Projects

The South African Penguin has been listed as endangered by the International Union for Conservation of Nature. Major histocompatibility complex (MHC) alleles provide valuable statistics because of their variation in terms of vertebrate genomes and are pertinent to immune and reproductive health. A greater number of MHC alleles correlates with survivability of a population because the genes control the immune and reproductive systems. Legacy research by Otterbein alumni and Dr. Simon Lawrance studied MHC samples from wild, in situ, and captive, ex situ, penguin populations. By comparing these populations' major histocompatibility complexes through biostatistical analysis, contributions to conservation of the …

Coastal Upwelling Enhances Abundance Of A Symbiotic Diazotroph (Ucyn-A) And Its Haptophyte Host In The Arctic Ocean, Corday R. Selden, Sveinn V. Einarsson, Kate E. Lowry, Katherine E. Crider, Robert S. Pickart, Peigen Lin, Carin J. Ashjian, P. Dreux Chappell

OES Faculty Publications

The apparently obligate symbiosis between the diazotroph Candidatus Atelocyanobacterium thalassa (UCYN-A) and its haptophyte host, Braarudosphaera bigelowii, has recently been found to fix dinitrogen (N²) in polar waters at rates (per cell) comparable to those observed in the tropical/subtropical oligotrophic ocean basins. This study presents the novel observation that this symbiosis increased in abundance during a wind-driven upwelling event along the Alaskan Beaufort shelfbreak. As upwelling relaxed, the relative abundance of B. bigelowii among eukaryotic phytoplankton increased most significantly in waters over the upper slope. As the host’s nitrogen demands are believed to be supplied primarily by UCYN-A, …

Production And Biological Activities Of Oligo Pectin From Early Immature Fruit Of Durio Zibethinus L., Aunchiya Pitaksa

Chulalongkorn University Theses and Dissertations (Chula ETD)

Early immature durian (EID) fruits, 30-45 days after anthesis with 6-12 cm in length, are considered agricultural waste from cultivation. It is known that durian rinds of mature fruits contain pectin, but there have been no reports on the pectin content of early immature durian (EID) fruits. Therefore, the objective of this study was to determine the pectin content in EID fruits. We extracted pectin from EID fruits using distilled water at different temperatures (25°C, 50°C, and 75°C) for 1 h to investigate pectin content. Instrumental analyses, including X-ray diffraction (XRD) and Fourier Transform Infrared Spectrometer (FT-IR), confirmed the presence …

Investigation Of Dna Hybridization In Localized Systems In Close Proximity, Ashley M. Sewsankar

Honors Undergraduate Theses

Hybridization of two or more DNA or RNA strands is well documented for the process taking place with all strands free in solution or when one strand is immobilized on a substrate. This study contributes to the investigation of the hybridization process when two single DNA strands (ssDNA) are in close proximity. We took advantage of an X sensor in which hybridization of four DNA strands enables the formation of a DNA four-way junction (crossover or X) structure. We immobilized multiple layers of crossover structures to study its hybridization being triggered by short ssDNA coming from solution and further investigate …

Peripheral And Central Glucose Flux In Type I Diabetes, Jelena Anna Juras

Theses and Dissertations--Neuroscience

Diabetes is a complex metabolic disorder, of which high blood glucose concentration is the primary hallmark. Type I diabetes mellitus (T1DM) is characterized by the lack of insulin production, due to a poorly understood autoinflammatory cascade. In the words of historian Barnett “Diabetes may no longer be a death sentence, but for more and more people in the 21st century, it will become a life sentence”, making it the focal point of many research groups. It is estimated that around 20 million individuals worldwide live with T1DM.

Effects of long-term chronically elevated blood glucose are not only seen in micro/macro-vascular …

Building Tools For Improved Modulation Of The Human Gabaa Receptor, A Central Nervous System Target For The Treatment Of Anxiety, Garrett Edward Zinck

Theses and Dissertations--Pharmacy

In the U.S., anxiety is recognized as an increasing range of mentally and physically debilitating psychiatric health disorders with significant economic repercussions. Over the last 20 years, several novel anti-anxiety therapies have entered the drug development pipeline, but none have made it to market.

The work in this dissertation focused on structurally modifying valerenic acid (VA), a structurally unique carboxylated sesquiterpene acid found in Valeriana officinalis. VA is putatively reported to have allosteric modulatory activity of the human GABA_A receptor, a ligand-gated ion channel responsible for attenuating neurotransmissions. Structural modeling of VA’s GABA_A receptor interaction suggests that …

Apoe Genotype And Cerebral Glucose Metabolism: A Multi-Omics Approach, Holden C. Williams

Theses and Dissertations--Physiology

Apolipoprotein E (APOE) is encoded by the APOE gene, present in humans as three main isoforms (E2, E3, and E4). E4 carriers face up to a 15-fold increased risk for developing late-onset Alzheimer’s disease (AD), while E2 carriers are protected. Understanding the risk conferred by E4 has been an extensive research focus for nearly three decades, but the exact mechanism has yet to be proven. Many studies have demonstrated attenuated roles of E4 in classical hallmarks of AD, notably amyloid processing and neurofibrillary formation, which normally present later in disease progression. How APOE influences hallmarks that present much earlier are …

Function And Expression Of Ribonucleotide Reductase-Encoding Genes In Flavobacterium Johnsoniae, Hunter Scott Doheny

All Graduate Theses, Dissertations, and Other Capstone Projects

Ribonucleotide reductases (RNRs) are essential enzymes that are involved in DNA synthesis. While this makes them ideal targets for antiproliferative drugs, most known RNR targeting agents are nonspecific. This poses a problem when considering antimicrobials, but several groups of bacteria have RNRs that utilize unique mechanisms that could be exploited if fully understood. One such bacteria, Flavobacterium johnsoniae, has the gene for a class Id RNR with a novel activation mechanism. Class Id RNRs belong to the aerobic class I RNRs and seem to have a unique metallocofactor and activation mechanism involving superoxide and manganese. The goal of this research …

Determining The Effects Of Chemical Exposure On Hepatocyte Mitochondrial Networks And Cell Viability, Bethany Eaton

All Master's Theses

Mitochondria are cellular organelles that are becoming more recently studied. One of their main functions is the production of energy through cellular respiration, which is crucial to cell life. However, they are also associated with numerous disease states. It is hypothesized that reactive oxygen species (ROS), largely produced in mitochondria, induce oxidative stress and affect mitochondrial morphology along with cell viability. This study compares chemical exposure of menadione, an ROS producer, and phthalates (plasticizers) on two mouse hepatocyte cell lines to determine the effects they have on mitochondrial morphology and cell viability. Three experiments were performed to analyze the effects …

Anti-Neuroinflammatory Effects Of Auricularia Polytricha Extracts On Bisphenol A (Bpa)-Induced Microglial Cell Activation And Reduction Of Hippocampal Cell Damage, Chanin Sillapachaiyaporn

Chulalongkorn University Theses and Dissertations (Chula ETD)

Bisphenol A (BPA) is widely used in the production of polycarbonate plastics, it has been reported that BPA can activate neuroinflammation. Neuroinflammation is a brain pathology that involves the high levels of pro-inflammatory mediators, including tumor necrosis factor-alpha (TNF-α). An excessive TNF-α expression could result in neuronal cell death and subsequently lead to neurodegeneration. Auricularia polytricha (AP) is an edible mushroom with several medicinal properties. Herein, the anti-neuroinflammatory effects of AP extracts against BPA-induced BV2 microglial inflammation were investigated. Hexane (APH) and ethanol (APE) extracts of AP inhibited BPA-induced neuroinflammation in BV2 cells by reducing the expression of pro-inflammatory cytokines. …