Biochemistry Commons^™

Cytotoxic Activity Of Triazole-Containing Alkyl Β-D-Glucopyranosides On A Human T-Cell Leukemia Cell Line, E. Davis Oldham, Larissa M. Nunes, Armando Varela-Ramirez, Stephen E. Rankin, Barbara L. Knutson, Renato J. Aguilera, Hans-Joachim Lehmler

Chemistry and Physics

Simple glycoside surfactants represent a class of chemicals that are produced from renewable raw materials. They are considered to be environmentally safe and, therefore, are increasingly used as pharmaceuticals, detergents, and personal care products. Although they display low to moderate toxicity in cells in culture, the underlying mechanisms of surfactant-mediated cytotoxicity are poorly investigated.

An Investigation Of Bag3 Knockdown And Its Effects On The Cytotoxicity Of Laromustine, Colin Sheehan

Honors Theses

Laromustine is a sulfonylhydrazine anticancer prodrug whose main cytotoxic arises from its ability to interfere with DNA replication of dividing cells. Multiple studies have suggested that Laromustine induces a form of cell death known as apoptosis. In a previous study investigating the mechanism of apoptosis, bcl2-associated athanogene 3 (BAG3) demonstrated significant upregulation in the presence of Laromustine. Given its anticancer ability, we selected BAG3 as a target for further investigation. BAG3 knockdown through transient shRNA transfections was performed in U138 glioblastoma multiforme cells and verified using qRT-PCR analysis. Finally, cell death assays were used to assess Laromustine’s cytotoxic effect on …

Divergent Responses Of Atlantic Coastal And Oceanic Synechococcus To Iron Limitation, Katherine R. M. Mackey, Anton F. Post, Matthew R. Mcilvin, Gregory A. Cutter, Seth G. John, Mak A. Saito

OES Faculty Publications

Marine Synechococcus are some of the most diverse and ubiquitous phytoplankton, and iron (Fe) is an essential micronutrient that limits productivity in many parts of the ocean. To investigate how coastal and oceanic Atlantic Synechococcus strains acclimate to Fe availability, we compared the growth, photophysiology, and quantitative proteomics of two Synechococcus strains from different Fe regimes. Synechococcus strain WH8102, from a region in the southern Sargasso Sea that receives substantial dust deposition, showed impaired growth and photophysiology as Fe declined, yet used few acclimation responses. Coastal WH8020, from the dynamic, seasonally variable New England shelf, displayed a multitiered, hierarchical cascade …

The Relative Importance Of Methanogenesis In The Decomposition Of Organic Matter In Northern Peatlands, J. Elizabeth Corbett, Malak M. Tfaily, David J. Burdige, Paul H. Glaser, Jeffrey P. Chanton

OES Faculty Publications

Using an isotope-mass balance approach and assuming the equimolar production of CO₂ and CH₄ from methanogenesis (e.g., anaerobic decomposition of cellulose), we calculate that the proportion of total CO₂ production from methanogenesis varies from 37 to 83% across a variety of northern peatlands. In a relative sense, methanogenesis was a more important pathway for decomposition in bogs (80 ± 13% of CO₂ production) than in fens (64 ± 5.7% of CO₂ production), but because fens contain more labile substrates they may support higher CH4 production overall. The concentration of CO₂ produced from methanogenesis (CO …

The Geotraces Intermediate Data Product 2014, Edward Mawji, Reiner Schlitzer, Elena M. Dodas, Cyril Abadie, Wafa Abouchami, Robert F. Anderson, Gregory A. Cutter

OES Faculty Publications

The GEOTRACES Intermediate Data Product 2014 (IDP2014) is the first publicly available data product of the international GEOTRACES programme, and contains data measured and quality controlled before the end of 2013. It consists of two parts: (1) a compilation of digital data for more than 200 trace elements and isotopes (TEls) as well as classical hydrographic parameters, and (2) the eGEOTRACES Electronic Atlas providing a strongly inter-linked on-line atlas including more than 300 section plots and 90 animated 3D scenes. The IDP2014 covers the Atlantic, Arctic, and Indian oceans, exhibiting highest data density in the Atlantic. The TEI data in …

Genetic Indicators Of Iron Limitation In Wild Populations Of Thalassiosira Oceanica From The Northeast Pacific Ocean, P. Dreux Chappell, Leann P. Whitney, Joselynn R. Wallace, Adam I. Darer, Samua Jean-Charles, Bethany D. Jenkins

OES Faculty Publications

Assessing the iron (Fe) nutritional status of natural diatom populations has proven challenging as physiological and molecular responses can differ in diatoms of the same genus. We evaluated expression of genes encoding flavodoxin (FLDA1) and an Fe-starvation induced protein (ISIP3) as indicators of Fe limitation in the marine diatom Thalassiosira oceanica. The specificity of the response to Fe limitation was tested in cultures grown under Fe-and macronutrient-deficient conditions, as well as throughout the diurnal light cycle. Both genes showed a robust and specific response to Fe limitation in laboratory cultures and were detected in small volume samples collected from …

Elucidation Of A Novel Pathway In Staphylococcus Aureus: The Essential Site-Specific Processing Of Ribosomal Protein L27, Erin A. Wall

Theses and Dissertations

Ribosomal protein L27 is a component of the eubacterial large ribosomal subunit that has been shown to play a critical role in substrate stabilization during protein synthesis. This function is mediated by the L27 N-terminus, which protrudes into the peptidyl transferase center where it interacts with both A-site and P-site tRNAs as well as with 23S rRNA. We observed that L27 in S. aureus and other Firmicutes is encoded with a short N-terminal extension that is not present in most Gram-negative organisms, and is absent from mature ribosomes. The extension contains a conserved cleavage motif; nine N-terminal amino acids are …

Regulation Of Tie2 Extracellular Complex Formation In Angiogenesis, Annamarie Dalton

Theses and Dissertations

Pathological angiogenesis is an essential component of tumor growth, development, and metastasis for which few effective therapeutic options exist. Though many cancer therapies target the function of cell surface receptors, mechanisms regulating membrane receptor crosstalk remain unclear. Two important families of receptors in angiogenesis, the Ties and Integrins, respond to the extracellular environment via outside-in and, in the case of Integrins, also inside- out signaling. Recent reports showed that the endothelial specific tyrosine kinase receptor, Tie2, forms complexes with two of the endothelial Integrin heterodimers, α₅β₁ and α_Vβ₃, providing a convenient mechanism for …

Characterization Of A Novel Protease In Staphylococcus Aureus, Adam L. Johnson

Theses and Dissertations

A newly discovered cysteine protease, Prp, has been shown to perform an essential, site-specific cleavage of ribosomal protein L27 in Staphylococcus aureus. In Firmicutes and related bacteria, ribosomal protein L27 is encoded with a conserved N-terminal extension that must be removed to expose residues critical for ribosome function. Uncleavable and pre-cleaved variants were unable to complement an L27 deletion in S. aureus, indicating that this N-terminal processing event is essential and likely plays an important regulatory role. The gene encoding the responsible protease (prp) has been shown to be essential, and is found in all organisms …

Numerical Geometry Of Map And Model Assessment, Willy Wriggers, Jing He

Mechanical & Aerospace Engineering Faculty Publications

We are describing best practices and assessment strategies for the atomic interpretation of cryo-electron microscopy (cryo-EM) maps. Multiscale numerical geometry strategies in the Situs package and in secondary structure detection software are currently evolving due to the recent increases in cryo-EM resolution. Criteria that aim to predict the accuracy of fitted atomic models at low (worse than 8 angstrom) and medium (4-8 angstrom) resolutions remain challenging. However, a high level of confidence in atomic models can be achieved by combining such criteria. The observed errors are due to map-model discrepancies and due to the effect of imperfect global docking strategies. …

The Role Of Rnai In Downregulation Of Physcomitrella Patens Defense Genes And The Preliminary Steps Of Peg Mediated Transformation Of Mosses, Adam Beswick

Undergraduate Honors Thesis Collection

When attacked by a pathogen, the moss Physcomitrella patens will undergo both a hypersensitive response (HR) as well as a systematic acquired resistance (SAR) response. The SAR response turns on genes that ready the plant for future pathogen attacks. The hormone jasmonic acid (JA) is one of the products of SAR response in P. patens. In this study interference RNA (RNAi) was used to decrease gene expression of the allene oxide cyclase (ACe) gene, a key gene in the production pathway of JA. Using quantitative reverse transcriptase polymerase chain reaction (qRT-PCR), RNAi was found to significantly lower ACC gene levels …

Design And Synthesis Of Isatin-Based Caspase Inhibitors For Ruthenium Caging Applications, Kasun Chinthaka Ratnayake

Wayne State University Theses

ABSTRACT

DESIGN AND SYNTHESIS OF ISATIN BASED CASPASE INHIBITORS FOR RUTHENIUM CAGING APPLICATIONS

by

KASUN CHINTHAKA RATNAYAKE

August 2015

Advisor: Jeremy J. Kodanko, Ph.D.

Major: Chemistry (Organic)

Degree: Master of Science

Apoptosis is the energy dependent programmed cell death. Improper function of apoptosis could lead to diseases such as cancers, strokes, Alziemer’s disease. Caspases are the enzymes involved in the later stage of this process. Peptidyl and non-peptidyl caspase inhibitors have been synthesized recently. These non-peptidyl compound classes which consist of pyrrolidinyl-5-sulfo isatins have showed a greater potency against executioner caspases, caspase-3 and -7. According to literature and for further …

The Structural Heterogeneity And Dynamics Of Base Stacking And Unstacking In Nucleic Acids, Ada Anna Sedova

Legacy Theses & Dissertations (2009 - 2024)

Base stacking provides stability to nucleic acid duplexes, and base unstacking is involved in numerous biological functions related to nucleic acids, including replication, repair, transcription, and translation. The patterns of base stacking and unstacking in available nucleic acid crystal structures were classified after separation into their individual single strand dinucleotide components and clustering using a k-means-based ensemble clustering method. The A- and B-form proximity of these dinucleotide structures were assessed to discover that RNA dinucleotides can approach B-form-like structures. Umbrella sampling molecular dynamics simulations were used to obtain the potential of mean force profiles for base unstacking at 5'-termini for …

Rna Aptamer Mediated Manipulation Of The 70 Kilodalton Heat Shock Protein Chaperone Machinery, Deepak Thirunavukarasu

Legacy Theses & Dissertations (2009 - 2024)

Protein quality control involves refolding of damaged proteins and facilitating degradation of irreparable proteins. Understanding the protein quality control mechanism is critical, since defects in it has been implicated in a number of age-related diseases like neurodegenerative diseases and also in cancer. A vast network of molecular chaperones and proteolytic systems collaborate to maintain protein quality control. The 70 kilodalton Heat shock protein (Hsp70) is a highly conserved and ubiquitous chaperone, which interacts with a variety of protein substrates including newly synthesized polypeptides, unfolded, partially misfolded and native proteins to maintain protein quality control. Hsp70 chaperone function is coupled to …

Novel Nmr Based Technologies To Study Macromolecular Structures, Subhabrata Majumder

Legacy Theses & Dissertations (2009 - 2024)

Nuclear Magnetic Resonance Spectroscopy (NMR) is one of the principle tools in structural biology to probe macromolecular structures and interactions. The atomic resolution afforded by this technique has been widely used to probe protein-protein, and protein-ligand interactions in-vitro. However, the natural milieu of the proteins is the living cell and the cellular cytoplasm is extremely heterogeneous. The NMR studies of folded protein in-cell, till now, have been limited by non-specific interactions of the cytosol. This thesis outlays a general methodology to study protein structure/interactions inside the living cells using NMR. In a closely related objective, it also describes the use …

Hiv Integrase Mechanisms Of Resistance To Raltegravir, Elvitegravir, And Dolutegravir, Kyla Nicole Ross

Wayne State University Theses

ABSTRACT

HIV INTEGRASE MECHANISMS OF RESISTANCE TO RALTEGRAVIR, ELVITEGRAVIR, AND DOLUTEGRAVIR

by

KYLA ROSS

December 2015

Advisor: Dr. Ladislau Kovari

Major: Biochemistry and Molecular Biology

Degree: Master of Science

HIV-1 integrase (HIV-1 IN or IN) is a multimeric enzyme that integrates the HIV-1 genome into the chromosomes of infected CD4+ T-cells. Currently there are three FDA approved HIV-1 IN strand transfer inhibitors (INSTIs) used in clinical practice: raltegravir (RAL), elvitegravir (ELV), and dolutegravir (DTG). The [Q148H], [Q148H, G140S], [Q148R], [Q148R, G140A] and [N155H, E92Q] mutations decrease IN susceptibility to RAL and ELV and may result in therapeutic failure. As an …

Expression And Functional Analysis Of Lipids And Glycolipids From The Mammal-Dwelling Stages Of Trypanosoma Cruzi, Felipe Gazos Lopes

Open Access Theses & Dissertations

Trypanosoma cruzi is the causative agent of the life-threatening Chagas disease, in which increased platelet aggregation related to myocarditis is observed. Platelet-activating factor (PAF) is a potent intercellular lipid mediator and second messenger that exerts its activity through a PAF-specific receptor (PAFR). Previous data from our group suggested that T. cruzi synthesizes a phospholipid with PAF-like activity. The structure of T. cruzi PAF-like molecule, however, remains elusive. Here, we have purified and structurally characterized the putative T. cruzi PAF-like molecule by electrospray ionization-tandem mass spectrometry (ESI-MS/MS). Our ESI-MS/MS data demonstrated that the T. cruzi PAF-like molecule is actually a lysophosphatidylcholine …

Role Of Small Molecules In Rescuing Protein Folding Under Oxidative Stress, Mahmoud Fawzi Megahed Helal Khalil

Open Access Theses & Dissertations

Increased levels of nitrosative stress intracellularly within the endoplasmic reticulum is a key factor involvled in the pathogenesis of both Parkinson's (PD) and Alzheimer's (AD) diseases. Previous in-vitro studies in our lab showed that increased levels of nitrosative stress lead to aggregation of misfolded proteins and formation of Lewy Bodies, the main biomarker of PD and AD diseases. Although this was mainly through nitrosylation of Protein Disulfide Isomerase (PDI), the chief endoplasmic reticulum (ER) resident oxidoreductase chaperone responsible for maturation of disulfide-bond-containing proteins, we demonstrate in this project that increased levels of nitrosative stress has an additional direct effect on …

Using Antenna Tile-Assisted Substrate Delivery To Improve Detection Limits Of Deoxyribozyme, Amanda J. Cox

HIM 1990-2015

One common limitation of enzymatic reactions is the diffusion of a substrate to the enzyme active site and/or the release of the reaction products. These reactions are known as diffusion –controlled. Overcoming this limitation may enable faster catalytic rates, which in the case of catalytic biosensors can potentially lower limits of detection of specific analyte. Here we created an artificial system to enable deoxyribozyme (Dz) 10-23 based biosensor to overcome its diffusion limit. The sensor consists of the two probe strands, which bind to the analyzed nucleic acid by Watson-Crick base pairs and, upon binding re-form the catalytic core of …

Chemoenzymatic Studies To Enhance The Chemical Space Of Natural Products, Jhong-Min Chen

Theses and Dissertations--Pharmacy

Natural products provide some of the most potent anticancer agents and offer a template for new drug design or improvement with the advantage of an enormous chemical space. The overall goal of this thesis research is to enhance the chemical space of two natural products in order to generate novel drugs with better in vivo bioactivities than the original natural products.

Polycarcin V (PV) is a gilvocarcin-type antitumor agent with similar structure and comparable bioactivity with the principle compound of this group, gilvocarcin V (GV). Modest modifications of the polyketide-derived tetracyclic core of GV had been accomplished, but the most …

Imber- Research For Marine Sustainability: Synthesis And The Way Forward, Eileen Hofmann, Alida Bundy, Ken Drinkwater, Alberto R. Piola, Bernard Avril, Carol Robinson

CCPO Publications

The Integrated Marine Biogeochemistry and Ecosystem Research (IMBER) project aims at developing a comprehensive understanding of and accurate predictive capacity of ocean responses to accelerating global change and the consequent effects on the Earth system and human society. Understanding the changing ecology and biogeochemistry of marine ecosystems and their sensitivity and resilience to multiple drivers, pressures and stressors is critical to developing responses that will help reduce the vulnerability of marine-dependent human communities. This overview of the IMBER project provides a synthesis of project achievements and highlights the value of collaborative, interdisciplinary, integrated research approaches as developed and implemented through …

Sharp Rna Recognition Motif Optimizations, Extensions, And Mutations For Use In 2d And 3d Nmr Experiments, Shaun M. Christie

Williams Honors College, Honors Research Projects

SMRT/HDAC Associated Repressor Protein interacts with the long noncoding RNA, produced by SRA, by binding at the RRMs. Three projects were done to prepare the truncated proteins for use in 2D and 3D NMR experiments. The first focuses on RRM 3 and its optimization during the purification process. The second focuses on RRM 2-4, which was found to be missing two alpha helices that may be important for protein stability. These helices can also interact with RRM 3 as well due to the tight association of RRMs 3 and 4. The two step PCR extension of RRM 2-4 was assumed …

An Nmr-Guided Approach To The Isolation Of Secondary Metabolites From Nrps And Pks Gene Clusters, Connor Craig

Honors Theses

Secondary metabolites continue to offer a promising source of novel chemical entities with therapeutic bioactivities. Our research aims to isolate secondary metabolites produced by non-ribosomal peptide synthetase (NRPS) and polyketide synthase (PKS) constructs. A metagenomic library was created from the marine bacterium Pseudoalteromonas sp., which was isolated from the Chesapeake Bay sponge Halichondria bowerbanki. Using a functional screen for PPTase activity we were able to identify colonies that contained NRPS and PKS gene clusters. Cultures of this microbe have been produced and analyzed using a combination of chromatography and 1H, 13C, HMBC, HSQC, COSY, AND NOESY NMR spectra. …

Development Of A Genetic Over-Expression System For The Freshwater Sponge Ephydatia Muelleri, Joe Walsh

Honors Theses

The aim of this work is to develop an over-expression system for Ephydatia muelleri. Preliminary work by Klaske Schippers (Schippers, 2013) showed sponges were induced to transcribe reporter genes driven by the widely used cytomegalovirus promoter (CMV). Building off Schippers work, newly identified native Ephydatia promoters were identified from the genome and verified to drive expression ofreporter genes. Validated over-expression vectors and transfection technology will allow researchers around the world who are working with this organism to ask questions about cell specification, gene regulation and animal development.

Sestrin2, A Regulator Of Thermogenesis And Mitohormesis In Brown Adipose Tissue, Seung-Hyun Ro, Ian Semple, Allison Ho, Hwan-Woo Park, Jun Hee Lee

Department of Biochemistry: Faculty Publications

Sestrin2 is a stress-inducible protein that functions as an antioxidant and inhibitor of mTOR complex 1. In a recent study, we found that Sestrin2 overexpression in brown adipocytes interfered with normal metabolism by reducing mitochondrial respiration through the suppression of uncoupling protein 1 (UCP1) expression. The metabolic effects of Sestrin2 in brown adipocytes were dependent on its antioxidant activity, and chemical antioxidants produced similar effects in inhibiting UCP1-dependent thermogenesis. These observations suggest that low levels of reactive oxygen species (ROS) in brown adipocytes can actually be beneficial and necessary for proper metabolic homeostasis. In addition, considering that Sestrins are ROS …

On The Protective Properties Of Glycine Based Osmolytes In A Thiol Reducing Environment, John Michael Hausman

Dissertations, Master's Theses and Master's Reports - Open

The protective properties of osmolytes have been studied intently for decades. Originally used to aid in the crystallization of proteins in x-ray diffraction studies, these cosolvents have been shown to reverse protein denaturation and aggregation. Osmolytes aid extremophiles in surviving harsh environments by preferentially excluding themselves from the surface of the protein, thus directing water molecules to the protein’s surface. These osmolytes are naturally found in many health foods and also in many daily use products such as shampoo. Due to their osmoprotective effect their use in everyday consumer product is increasing. Consumers also supplement their diets with thiol-based antioxidants …

The Optimization Of Mitoneet Synthesis, Purification And Mutation Stability In The [2fe-2s] Cluster, Alexandria Defabio

Williams Honors College, Honors Research Projects

MitoNEET, a mitochondrial membrane protein with an unsymmetrical Fe-S cluster coordination, was compared to similar proteins within the Rieske and Ferredoxin families. Point mutations were introduced via site-directed mutagenesis to induce stability, greater retention of the cluster, and to uncover structural limitations of the protein. Mutations were made within the cluster coordination and within the hydrophobic core of the protein. Some of the cluster mutations displayed a natural affinity for nickel during immobilized metal-ion affinity chromatography. It is possible that these mutations aid in the formation of a chelate when exposed to nickel. Spectroscopic monitoring of changes in cluster stability …

Evaluation Of Small Molecules On The Excitatory Amino Acid Transporter 3 (Eaat3) For The Treatment Of Ocd, Emmanuel Zubia

Open Access Theses & Dissertations

We seek to discover new drug candidates for the excitatory amino acid transporter 3 (EAAT3) for the treatment of Obsessive Compulsive Disorder (OCD). We hypothesize that decreasing the glutamatergic transmission via EAAT3 intervention will create an amelioration of the symptoms of OCD. For this we have prepared in-silico binding calculations to identify a better compound that can stimulate EAAT3 and decrease glutamatergic transmission. This research will help us further understand and elucidate the role of glutamate in the neural mechanisms of this illness, which to date remain inconclusive. Those areas of study are significant because, until now, there is no …

Membrane Protein Spatial Organization In Mdck Cell Cultures, Rachel E. Neugebauer

Williams Honors College, Honors Research Projects

Studies on the organization of membrane proteins such as GPCRs in live cells help to draw important conclusions regarding cellular communication, and have become a significant topic in drug therapy development. Observing proteins in MDCK cells, which are able to form three-dimensional cultures, provides an intermediate step to better understanding the organization and behavior of these proteins in a tissue-like culture. In this study, fluorescent stains were used on fixed cells to show the morphological differences between MDCK cells in monolayer cultures and three-dimensional cultures, which form hollow, spherical cysts of tightly packed cells. Monolayer cells were transfected to view …

Evaluation Of The Signature Molecular Descriptor With Blosum62 And An All-Atom Description For Use In Sequence Alignment Of Proteins, Lindsay M. Aichinger

Williams Honors College, Honors Research Projects

This Honors Project focused on a few aspects of this topic. The second is comparing the molecular signature kernels to three of the BLOSUM matrices (30, 62, and 90) to test the accuracy of the mathematical model. The kernel matrix was manipulated in order to improve the relationship by focusing on side groups and also by changing how the structure was represented in the matrix by increasing the initial height distance from the central atom (Height 1 and Height 2 included).

There were multiple design constraints for this project. The first was the comparison with the BLOSUM matrices (30, 62, …