Biochemistry Commons^™

Chain Length Effect On The Structure And Stability Of Antimicrobial Peptides Of The (Rw)N Series, Nsoki Phambu, Bashiyar Almarwani, Arlette M. Garcia, Nafisa S. Hamza, Amira Muhsen, Jacqueline E. Baidoo, Anderson Sunda-Meya

Chemistry Faculty Research

Three peptides containing (RW)n-NH2 units (where n=4, 6, and 8) have been chosen to study the effect of the chain length on the structure and stability of the peptide using Fourier transform infrared (FTIR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC) techniques. Their interactions with Escherichia coli (E. coli) membrane mimetic vesicles are discussed. Infrared results indicate that addition of (RW)n-NH2 units increases intermolecular H bonds with antiparallel orientation. TGA and DSC results reveal that (RW)6-NH2 shows the optimal chain length in terms of stability and all three peptides show a preferential interaction with one …

Characterization Of Genes Involved In Phycobiliprotein Biosynthesis In Fremyella Diplosiphon And Thermosynechococcus Elongatus, Christina M. Kronfel

LSU New Orleans Theses and Dissertations

Cyanobacteria are photosynthetic organisms that efficiently capture light by utilizing the light-harvesting complexes called phycobilisomes. In many cyanobacteria, phycobilisomes are composed of an allophycocyanin core with phycocyanin and phycoerythrin (PE) rods radiating from the core. These phycobiliproteins have multiple bilin chromophores, such as phycoerythrobilin (PEB), covalently attached to specific cysteine (Cys) residues for efficient photosynthetic light capture. Chromophore ligation on phycobiliprotein subunits occurs through bilin lyase catalyzed reactions.

This study mainly focuses on characterizing the roles of enzymes that are involved in the biosynthetic pathway of the phycobiliproteins within two cyanobacteria Thermosynechococcus elongatus and Fremyella diplosiphon. A combination of molecular …

Desulfination By 2′-Hydroxybiphenyl-2-Sulfinate Desulfinase Proceeds Via Electrophilic Aromatic Substitution By The Cysteine-27 Proton, Inacrist Geronimo, Shawn R. Nigam, Christina M. Payne

Chemical and Materials Engineering Faculty Publications

Biodesulfurization is an attractive option for enzymatically removing sulfur from the recalcitrant thiophenic derivatives that comprise the majority of organosulfur compounds remaining in hydrotreated petroleum products. Desulfurization in the bacteria Rhodococcus erythropolis follows a four-step pathway culminating in C–S bond cleavage in the 2′-hydroxybiphenyl-2-sulfinate (HBPS) intermediate to yield 2-hydroxybiphenyl and bisulfite. The reaction, catalyzed by 2′-hydroxybiphenyl-2-sulfinate desulfinase (DszB), is the rate-limiting step and also the least understood, as experimental evidence points to a mechanism unlike that of other desulfinases. On the basis of structural and biochemical evidence, two possible mechanisms have been proposed: nucleophilic addition and electrophilic aromatic substitution. Density …

Rosa Hybrid Gene Gapc Is Mutated In The Presence Of The Rose Rosette Virus, William A. Beams, Eva L. Burelos, Charles C. Hundley, Landon R. Dame, Laura G. Sims, Jacob J. Adler

Kentucky Journal of Undergraduate Scholarship

Rose Rosette Disease (RRD) harms the global rose supply by modification of the growth and development in rose cultivar. RRD spreads via a negative-sense RNA plant virus transmitted by eriophyid mites. Importantly, there is no pre-existing knowledge about the biochemistry by which this virus debilitates roses. Here we implicate glyceraldehyde-3-phosphate dehydrogenase (GAPDH), one of the major metabolic enzymes in plants, as a possible target of the virus. Genomic DNA of the cytosolic form of the protein encoded by GAPC was extracted from both virally-infected and non-infected samples of the Rosa hybrid cultivar Rosa Tropicana. The sequence results provided several distinct …

B7h6: A Cancer Biomarker For The Development Of Novel Immunotherapy Approaches, Mariana Phillips

Seton Hall University Dissertations and Theses (ETDs)

Cancer-based immunotherapy has led the evolution of biologics that can stimulate immune responses towards tumor eradication. The synthesis of small to intermediate size molecules with the targeting and effector functions of mAb may represent a novel class of immunotherapeutics that may overcome the limitations of their biological counterparts.Towards this objective, B7H6 has been identified as a protein ligand localized on the cell surface of transformed tumor cells. B7H6 binds specifically to the activating receptor NKp30, constitutively expressed on all resting and active NK cells. Upon ligand:receptor binding, B7H6 triggers NK cell activation and release of chemokines and pro-inflammatory cytokines such …

Buried Alive: Urban Stream Burial In Grand Rapids, Michigan, Tanner Vincent

Student Papers and Reports

In the decades between 1913 and 1967, Silver and Coldbrook Creeks vanished from the urban landscape in the rapidly growing city of Grand Rapids, Michigan. A U.S. Geological Survey (USGS) map of Grand Rapids from 1914 shows both Silver and Coldbrook Creeks emptying into the Grand River west of their headwaters south and north of Reeds Lake, respectively. By 1967, the year a topographical map of Grand Rapids was created at a scale as fine as that of the 1914 map, both Silver and Coldbrook Creek had been erased from the landscape of Grand Rapids. A closer look at the …

Cloning, Purification, And Biochemical Characterization Of Human Prolyl Endopeptidase, Travis K. Moore

Electronic Theses and Dissertations

Eurygaster integriceps Puton, common name sunn Pest, is one of the primary sources of wheat crop wastes in North Africa, Middle East, and Eastern Europe. It feeds by injecting the wheat grain with an enzyme characterized as prolyl endoprotease (spPEP) that breaks down Gluten, the wheat’s main constitutive protein necessary for bread production (Darkoh et al., 2010). Previously, it has been shown that peptides isolated from Lactobacillus hydrolysates of caseins in bovine milk are able to inhibit mammalian PEP in colon cells, as well as bacterial PEP (Juillerat-Jeanneret et al., 2010). While recombinant versions of these peptides are also potential …

Studies On The Effect Of Glycolysis And Pi(3,5)P2 On V-Atpase Activity, Dennis Ralph Dominguez

Biomedical Sciences ETDs

We studied two signals that regulate the yeast vacuolar proton pump, V-ATPase, glucose and PI(3,5)P2.  V-ATPase regulation by glucose is linked to the glycolytic enzyme PFK-1. Chapter one investigates the relationship between V-ATPase and glycolysis in cells overexpressing the PFK-1 subunit Pfk2p.  We measured: (i) PFK-1 activity to determine the effect on PFK-1 function; and (ii) NADH autofluorescence to determine the effect on glycolysis. PFK2 overexpression decreased PFK-1 catalytic activity. However, the NADH synthesis rate increased by 1.4 – 2.6-fold, suggesting that excess Pfk2p enhanced the apparent glycolytic capacity of the cells. Vacuolar acidification was measured after the glucose concentration …

Predicting Outcomes Of Hormone And Chemotherapy In The Molecular Taxonomy Of Breast Cancer International Consortium (Metabric) Study By Biochemically-Inspired Machine Learning, Peter Rogan, Eliseos J. Mucaki, Katherina Baranova, Huy Q. Pham, Iman Rezaeian, Dimo Angelov, Alioune Ngom, Luis Rueda

Biochemistry Publications

Genomic aberrations and gene expression-defined subtypes in the large METABRIC patient cohort have been used to stratify and predict survival. The present study used normalized gene expression signatures of paclitaxel drug response to predict outcome for different survival times in METABRIC patients receiving hormone (HT) and, in some cases, chemotherapy (CT) agents. This machine learning method, which distinguishes sensitivity vs. resistance in breast cancer cell lines and validates predictions in patients; was also used to derive gene signatures of other HT (tamoxifen) and CT agents (methotrexate, epirubicin, doxorubicin, and 5-fluorouracil) used in METABRIC. Paclitaxel gene signatures exhibited the best performance, …

Molecularly Targeted Nanomedicine: Role Of Hsp90 Inhibitor And Sophorolipids In The Treatment Of Lung Cancer, Shuguftha Naz Ms

Electronic Theses & Dissertations

Lactonic sophorolipids (LSL) are a class of enzymatically modified glycolipids known to have HDAC inhibition activity and anticancer properties. Ganetespib (GT), an Hsp90 inhibitor, is known for its superior antitumor activity in several K-RAS mutant Non-Small-Cell Lung Cancer (NSCLC) cells. In this study, a new anti-oxidant nanoplatform is formulated using the combination of these two drugs, LSL and GT, in order to target both HDAC inhibition and Hsp90 signaling pathways in NSCLC. Nanoceria (NC) is an excellent redox platform will be specifically used to supplement the therapeutic potency of these drugs in the effective treatment of NSCLC. We hypothesized that …

The Role Of Exosomes In Prostate Field Cancerization, Julie Nguyen

Student Scholar Symposium Abstracts and Posters

Field cancerization is formally defined as the presence of molecular alterations in structurally normal tissues adjacent to tumors. Currently, the etiology of prostate field cancerization is still unknown. We hypothesize that exosomes (vesicles excreted by cells that may contain protein, lipids, or RNA) are released by tumors and are endocytosed by adjacent normal cells converting them into abnormal cells, thereby aiding cancer progression. The following biomarkers have been associated with field cancerization: MIC-1, PDGF-A, FASN, and EGR-1, while markers for exosomes are CD-9, CD-63, and PSMA. To test this hypothesis, exosomes were isolated from human prostate cancer cell models LNCaP …

Hydrogen Peroxide Inhibition Of Bicupin Oxalate Oxidase, John M. Goodwin, Hassan Rana, Joan Ndungu, Gaurab Chakrabarti, Ellen W. Moomaw

Faculty Articles

Oxalate oxidase is a manganese containing enzyme that catalyzes the oxidation of oxalate to carbon dioxide in a reaction that is coupled with the reduction of oxygen to hydrogen peroxide. Oxalate oxidase from Ceriporiopsis subvermispora (CsOxOx) is the first fungal and bicupin enzyme identified that catalyzes this reaction. Potential applications of oxalate oxidase for use in pancreatic cancer treatment, to prevent scaling in paper pulping, and in biofuel cells have highlighted the need to understand the extent of the hydrogen peroxide inhibition of the CsOxOx catalyzed oxidation of oxalate. We apply a membrane inlet mass spectrometry (MIMS) assay to directly …

I) Hv1, Lbp And Lcf Reconstitution In Liposomes Ii) Signed, Sealed, And Delivered: Cpp Technology Delivers Active Protein Cargo, Aaron I. Ledet

Master of Science in Chemical Sciences Theses

The first half of this thesis focuses on bioluminescence within the Lingulodinium polyedrum dinoflagellates. In this species, the organelle termed “scintillon” houses the components involved in bioluminescence: Luciferin Binding Protein (LBP), Luciferase (LCF), voltage-gated proton channel (Hv1), as well as the substrate Luciferin (LH₂). Bioluminescence is triggered by an internal drop in pH of the scintillon initiated by the voltage activation of Hv1 in the membrane. The first focus of this study is to use a synthetic scintillon—a liposome that contains the purified proteins and substrate—to mimic the observed system. Liposomes containing LCF, LBP, and LH₂ had …

Altered Na, K- Atpase Isoform Expression In Artemia Franciscana In Response To Hypersaline Environments, Jessica Drenth

Theses and Dissertations

The Na,K-ATPase (NKA) is an essential membrane pump that helps to establish cell ion gradients, and regulate intracellular salt in many organisms. One such species, Artemia franciscana (brine shrimp), extreme halophiles which live in hypersaline environments, expresses 2 distinct α-catalytic subunits of the NKA. One of these subunits, α2-(KK), has two key lysine substitutions located within the cation binding sites. Prior work has demonstrated this specific subunit may be directly involved in brine shrimp adaptation to their extreme environments. However, the precise molecular and physiological effects of α2-(KK) have not been entirely elucidated. I determined through immunohistochemistry that my initial …

Aberrant Glycosylation In Pancreatic Cancer Progression, Seema Chugh

Theses & Dissertations

Aberrant changes in O-glycosylation patterns underlie pancreatic ductal adenocarcinoma (PDAC) progression and metastasis. Glycosylation is a post-translational modification in which carbohydrate moieties are attached to the protein substrate. My dissertation is focused on mucin-type O-glycosylation, which is the predominant form of O-glycosylation and is regulated by a myriad of glycosyltransferases.

PDAC is one of the most lethal diseases and the mechanistic involvement of aberrant O-glycosylation in its progression and metastasis is unknown. The aberrant glycosylation refers to the appearance of unusual carbohydrate structures such as truncated carbohydrate antigens, often referred to as tumor-associated carbohydrate antigens.

In this dissertation, my goal …

The Rise And Fall Of The Bovine Corpus Luteum, Heather Talbott

Theses & Dissertations

This dissertation describes a study of the mechanisms regulating the genesis and subsequent involution of the temporary endocrine structure, the corpus luteum (CL), through the use of a bovine model. The CL is essential for maintaining a suitable uterine environment for embryo implantation and early development through secretion of the steroid hormone progesterone. The “Rise and Fall” of the CL occurs within each estrous cycle whereby the CL must form from the ruptured follicle, secrete sufficient progesterone for uterine maturation, and at the end of the cycle (or pregnancy) regress to allow new follicular development. During the rise of the …

Effects Of The Microenvironment Surrounding Cys433 In Arabidopsis Β-Amylase-1 And -3 On The Sensitivity To Glutathionylation By Nitrosoglutathione, Matthew R. Kohler

Senior Honors Projects, 2010-2019

Glutathionylation is a reversible post-translational modification of proteins involving the transfer of glutathione to the thiols of specific cysteine residues. While the mechanism behind glutathionylation is known, the specificity of cysteine glutathionylation is not understood. It is known, however, that the two main factors affecting the susceptibility to glutathionylation are the reactivity and accessibility of cysteines in proteins, which is determined by the microenvironment. Using β-amylases (BAMs) 1 and 3 from Arabidopsis thaliana, which have different sensitivities to nitrosoglutathione (GSNO), as a model, I attempted to provide insight into why some cysteines are glutathionylated by GSNO and others are …

Studies Into The Structure And Function Of Various Domains Of Obscurin And Titin, Rachel A. Policke

Senior Honors Projects, 2010-2019

Muscles give our bodies the ability to move by stretching and contracting. While contraction is accomplished by the well-known actin-myosin interaction, not much is known about stretch. Two integral muscle proteins involved in stretch are titin and obscurin; both are long rope-like protein molecules that seem to act as molecular springs. Mutations in these two proteins can lead to diseases such as hypertrophic cardiomyopathy and muscular dystrophy, as well as a variety of cancers. In an effort to understand muscle stretch and signaling on a more fundamental level, here we present the high resolution structure of obscurin Ig59, a domain …

The Role Of Semaphorin 5a In Pancreatic Cancer Progression And Metastasis, Sugandha Saxena Dr.

Theses & Dissertations

Pancreatic cancer (PC) is an aggressive disease with an overall 5-year survival rate of less than 7%, statistics that have not changed in almost five decades. Metastasis is one of the leading causes of mortality in PC. Accumulating evidence suggests that axon guidance molecules, such as semaphorins, are involved in cancer progression, invasion, and metastasis. Recent genomic characterization of pancreatic ductal adenocarcinoma revealed aberration in axon guidance pathway genes as well. Previous reports from our laboratory have identified one such molecule Semaphorin5A (SEMA5A) as a putative cell adhesion molecule which is involved in organ-specific homing during PC metastasis. My dissertation …

Epigenetic Regulation Of Salicylic Acid-Mediated Plant Defense, Phillip Key

Senior Theses

Plant pathogens remain a significant threat to the stability of modern agricultural systems, and the investigation of mechanisms to improve the security of food resources has led to the partial characterization of plant immune response. With this progress, there is a newfound ability to analyze the relative pathogen resistance capability of specifically modified organisms, and in doing so, it is possible to identify individual alterations that might play a role in creating a more robust immune response. In this study, ten Arabidopsis thaliana mutants were infiltrated with Pseudomonas syringae pv. morsprunorum alongside positive and negative control Col-0 Wild-Type and npr1-2. …