Biochemistry, Biophysics, and Structural Biology Commons^™

The Nifz Accessory Protein Has An Equivalent Function In Maturation Of Both Nitrogenase Mofe Protein P-Clusters, Emilio Jimenez-Vicente, Zhi-Yong Yang, Julia S. Martin Del Campo, Valarie L. Cash, Lance C. Seefeldt, Dennis R. Dean

Chemistry and Biochemistry Faculty Publications

The Mo-dependent nitrogenase comprises two interacting components called the Fe protein and the MoFe protein. The MoFe protein is an α₂β₂ heterotetramer that harbors two types of complex metalloclusters, both of which are necessary for N₂reduction. One type is a 7Fe-9S-Mo-C-homocitrate species designated FeMo-cofactor, which provides the N₂-binding catalytic site, and the other is an 8Fe-7S species designated the P-cluster, involved in mediating intercomponent electron transfer to FeMo-cofactor. The MoFe protein's catalytic partner, Fe protein, is also required for both FeMo-cofactor formation and the conversion of an immature form of P-clusters to the …

Peroxisomal Protein Defects Disrupt Coordinated Peroxisomal Processes And Affect Early Seedling Development Through Accumulating Toxic Catabolic Intermediates, Ying Li

Dissertations

Many peroxisomal proteins act in β-oxidation processes on a range of substrates. It is unclear how these proteins are coordinated to determine the flux of peroxisomal processes and meet the requirements for plant growth and development. Using mutant analysis and metabolic profiling, I examined proteins predicted to act in fatty acid and indole-butyric-acid (IBA) β-oxidation. ECH2 confers enoyl-CoA hydratase activity for the auxiliary β-oxidation of fatty acids with an even cis-unsaturated bond. ECH2 was suggested to function in IBA β-oxidation, as ech2 seedlings have altered IBA response. ech2 seedlings have reduced root length and cotyledon area. ech2 seedlings accumulate 3-hydroxyoctenoate …

The Transesterification Of Hickory Nuts Into Biodiesel Fuel, Hannah Trauger, Madilynn Dewell, Jahida A. Mendoza

Undergraduate Research Conference

• Biodiesel fuels can be produced from a fat and an alcohol via transesterification

• Hickory nuts have a high fat content (~60 % by weight)

• Can nuts from shagbark hickory (Carya ovata) be used to produce a biodiesel fuel using existing acidcatalyzed transesterification methods?

Longitudinal Study Of Lanana Creek, Bayler Barnes, Jackson T. Ortiz, Trace Washburn

Undergraduate Research Conference

A longitudinal study was done to collect data on the various conditions of LananaCreek in Nacogdoches, Texas over a seven week span from September 14 to November 2, 2018. The part of the creek studies is a 3.5 mile stretch from East Austin Street to Hoya Soccer Complex, mostly located on the campus of Stephen F. Austin State University. There were 6 different testing sites selected along this expanse. Collection of samples was performed by the General Chemistry I Honors class as part of the laboratory experience. Once collected, the samples were transported back to the lab for testing. The …

Extraction And Quantification Of Hydrolyzable Tannins In Acorns From Different Species Of Oak Trees (Quercus Spp.), Sarah Browning, Marshall E. Woodruff

Undergraduate Research Conference

Do white-tailed deer (Odocoileus virginianus) prefer to eat certain types of acorns based on tannin content?

Hydrolyzable tannins consist of gallate groups connected via ester linkages to a carbohydrate (D-glucose)

The Prussian Blue method was used to determine hydrolyzable tannin content

A Polyphasic Approach In Understanding Green Algal Ecology, Blia Lor

Biology Theses

Pithophora and Cladophora are two representative genera of the order Cladophorales as filamentous Chlorophyta. These two genera are major contributors to the total algal biomass of littoral communities in freshwater and shallow marine water and have been reported as nuisance algae as they proliferate fast with the influx of nutrients. However, the wide geographical distribution and the overlap of plastic morphological characteristics between the two genera have complicated taxonomic identification at species level and phylogenetic studies. In the present study, a population of a monospecific, filamentous algal community was collected in Jewell, Georgia from the Ogeechee River. The monospecific, filamentous …

Transcriptional Regulation Factors Of The Human Mitochondrial Aspartate/Glutamate Carrier Gene, Isoform 2 (Slc25a13): Usf1 As Basal Factor And Foxa2 As Activator In Liver Cells, Paolo Convertini, Simona Todisco, Francesco De Santis, Ilaria Pappalardo, Dominga Iacobazzi, Maria Antonietta Castiglione Morelli, Yvonne N. Fondufe-Mittendorf, Giuseppe Martelli, Ferdinando Palmieri, Vittoria Infantino

Molecular and Cellular Biochemistry Faculty Publications

Mitochondrial carriers catalyse the translocation of numerous metabolites across the inner mitochondrial membrane, playing a key role in different cell functions. For this reason, mitochondrial carrier gene expression needs tight regulation. The human SLC25A13 gene, encoding for the mitochondrial aspartate/glutamate carrier isoform 2 (AGC2), catalyses the electrogenic exchange of aspartate for glutamate plus a proton, thus taking part in many metabolic processes including the malate-aspartate shuttle. By the luciferase (LUC) activity of promoter deletion constructs we identified the putative promoter region, comprising the proximal promoter (−442 bp/−19 bp), as well as an enhancer region (−968 bp/−768 bp). Furthermore, with different …

The Presence Of Photoreceptor Sensilla In The Posterior Sucker Of Medicinal Leeches Inferred Through Functional Visual Response., Claire Spivey

Honors Theses

Medicinal leeches gather visual input from both its eyecups and photoreceptors across its body surface; each of its 21 midbody segments possesses 14 photoreceptive sensilla. It has been previously established that the posterior sucker is composed of seven body segments that are fused during embryogenesis. Similarly, four body segments fuse to create the anterior brain. There are five bilateral pairs of eyes located on the dorsal surface of the leech’s head and seven bilateral pairs of sensilla distributed over the surface of each midbody segment (Kretz et al., 1975). If no sensilla were lost during the fusion of the seven …

Mechanisms Of Oriented Cell Division And Their Roles In Tissue Development, Evan Blake Dewey

Biology ETDs

Properly executed cell division is crucial to development, maintenance, and longevity of multicellular organisms. Defects in both symmetric and asymmetric divisions can lead to improper developmental patterning, as well as genomic instability, disruption of tissue homeostasis, and cancer. Our research focuses on how regulators orchestrate proper cell divisions. Mushroom Body Defect (Mud) is one such regulator, and here we describe how Mud is regulated via the Hippo signaling pathway kinase Warts (Wts), showing Wts phosphorylates Mud to enhance interaction with the polarity protein Partner of Inscuteable, promoting spindle orientation activity. We next focus on another regulator, Shortstop (Shot), describing a …

Extracellular Vesicles As Biological Shuttles For Targeted Therapies., Stefania Raimondo, Gianluca Giavaresi, Aurelio Lorico, Riccardo Alessandro

College of Osteopathic Medicine (TUN) Publications and Research

The development of effective nanosystems for drug delivery represents a key challenge for the improvement of most current anticancer therapies. Recent progress in the understanding of structure and function of extracellular vesicles (EVs)-specialized membrane-bound nanocarriers for intercellular communication-suggests that they might also serve as optimal delivery systems of therapeutics. In addition to carrying proteins, lipids, DNA and different forms of RNAs, EVs can be engineered to deliver specific bioactive molecules to target cells. Exploitation of their molecular composition and physical properties, together with improvement in bio-techniques to modify their content are critical issues to target them to specific cells/tissues/organs. Here, …

Use Of Site-Directed Mutagenesis To Probe The Cystine Binding Site Within System Xc-, Kevin Catalfano

18th Annual Celebration of Undergraduate Research and Creative Activity (2019)

The Chase lab studies System xc-, which is a heterodimeric transporter that functions as a Na+-independent antiporter exchanging extracellular cystine for intracellular glutamate. The transporter functions as an obligate heterodimer and is comprised of two proteins, xCT, which functions specifically in amino acid exchange, and 4F2HC, which appears to play a role in transporter stability. System xc- belongs to the SLC7 family of transporters, which is further subdivided into the cationic amino acid transporters (CAT) and the L-type amino acid transporters (LAT), the latter of which is the subfamily which includes System xc-. In recent years, there have been advances …

Incorporation Of Egfr And Ron Receptors Into Nanodiscs, Cristina Flores-Cadengo

Biomedical Engineering ETDs

Understanding the structure-function relationship of membrane receptors is essential to comprehend the crosstalk between key signaling pathways. Aberrant trans-activation between receptors can lead to tumorigenesis. Two of these receptors known to be involved in cancer development are receptor tyrosine kinases (RTKs), RON (Recepteur d'Origine Nantais) and EGFR (Epidermal Growth Factor Receptor). There has been evidence of heterodimerization and crosstalk between these two receptors based on co-immunoprecipitation, however the structural requirements behind these interactions remain unknown. Structural studies could provide insights into these RTKs’ modes of dimerization and structure-function relationship. However, structural studies of full-length membrane proteins are often difficult due …

Design And Synthesis Of A Novel Lsoxazoline As A Potential Pam-Agonist, Josselyn Roosenberg

Honors Theses

Progression of Alzheimer's disease is associated with a loss of Ml receptor activation in the brain. However, a lack of clinical success following attempts to activate the Ml receptor at the orthosteric site has contributed to a transition towards the allosteric pocket of the receptor. Here, positive allosteric modulators (PAMs) interact to potentiate the acetylcholine response. Recent research proposes that optimization of PAM activity at the expense of intrinsic agonism may posit a means to limit adverse side effects. Therefore, this project proposes a design and synthesis of a novel isoxazoline as a potent PAM agent with weak intrinsic agonism.

Analysis Of Dl-Amino Acid Ratios In Eggshells Using Reverse Phase-High Pressure Liquid Chromatography, Gergana Milkova

Honors Theses

HPLC methodology was developed to determine the concentrations and ratios of D to L amino acids in emu and ostrich eggshells treated with heat at different temperatures . We aimed to determine an internal standard and how ratios were affected under different conditions. An HPLC method was determined that gave consistent retention times and satisfactory enantioseparation . Calibration curves for each amino acid were developed from single and multi-amino acid containing dilution series producing a model that most closely replicates the eggshell-extracted amino acids.

You Are What You Eat At Any Age: Carbon And Nitrogen Analysis Of Mummies From An Ancient Egyptian Necropolis, Stephen Funk, R. Paul Evans

Library/Life Sciences Undergraduate Poster Competition 2019

The BYU Egypt Project at Fag el-Gamus necropolis and adjacent Seila Pyramid has studied over 700 mummies excavated over the past 30 years. The necropolis includes an open area with densely located vertical burial shafts and a hill with horizontal burial shafts. The chronological and dietary history of the mummies was assessed using stable isotopy and 14C analysis of accessible biological samples.

Isolation And Characterization Of Novel Arginine-Derived Heterocyclic Amines, Nathaniel Srikureja

Honors Theses

Most known heterocyclic amines (HCAs) are potent mutagens present at significant concentrations in cooked meats, and can be synthesized from burned mixtures of L-creatin(in)e with various amino acids. We hypothesize that novel mutagenic HCAs may be synthesized from a heated plant-based food simulating binary amino acid mL'\:ture: L-arginine and L-threonine. A two-part solid phase extraction was used to separate nitrogen heterocycles from byproducts followed by prep­ HPLC and the Ames mutagenicity assay using Salmonella TA98 to determine the mutagenicity of various isolates. The results indicate that this binary amino acid mixture does not yield a mutagenic sample.

Novel Insights Into The Multifaceted Roles Of Blm In The Maintenance Of Genome Stability, Vivek M. Shastri

USF Tampa Graduate Theses and Dissertations

Genomic instability is a hallmark of disorders in which DNA replication and repair genes are dysfunctional. The tumor suppressor RECQ helicase gene BLM encodes the 3’-5’ DNA Bloom syndrome helicase BLM, which plays important roles during DNA replication, recombination and repair to maintain genome stability. Mutations within BLM cause Bloom syndrome, an autosomal recessive disorder characterized by growth defects, immunodeficiency, >10-fold higher sister chromatid exchange compared to normal cells, and an increased predisposition to a wide range of cancers from an early age. Single nucleotide polymorphisms or SNPs in BLM have been reported to be associated with susceptibility to a …

The One Health Approach To Toxoplasmosis: Epidemiology, Control, And Prevention Strategies, A. Alonso Aguirre, Travis Longcore, Michelle Barbieri, Haydee Dabritz, Dolores Hill, Patrice N. Klein, Christopher Lepczyk, Emily L. Lilly, Rima Mcleod, Judith Milcarsky, Caroline E. Murphy, Chunlei Su, Elizabeth Vanwormer, Robert Yolken, Grant C. Sizemore

School of Veterinary and Biomedical Sciences: Faculty Publications

One Health is a collaborative, interdisciplinary effort that seeks optimal health for people, animals, plants, and the environment. Toxoplasmosis, caused by Toxoplasma gondii, is an intracellular protozoan infection distributed worldwide, with a heteroxenous life cycle that practically affects all homeotherms and in which felines act as definitive reservoirs. Herein, we review the natural history of T. gondii, its transmission and impacts in humans, domestic animals, wildlife both terrestrial and aquatic, and ecosystems. The epidemiology, prevention, and control strategies are reviewed, with the objective of facilitating awareness of this disease and promoting transdisciplinary collaborations, integrative research, and capacity building among universities, …

Synthesis Of An Ideal Inhibitor For The Lpxc Enzyme, Taejun Lee

Honors Theses

Due to the growing need of antibiotics in modern day medicine, this study attempts to apply a method of medicinal chemistry that would create a novel inhibitor for a lesser known target of gram negative bacteria, the LpxC enzyme. This study proposes that a synthetic plan which consists of combining components of different molecules would create a more effective inhibitor. These components include a binding group for the active site of the enzyme, a hydrophobic chain which has been shown to interact with an allosteric site on the LpxC enzyme, and the isoxazoline ring which interacts with the zinc ion. …

The Modified Synchronization Modulation Technique Revealed Mechanisms Of Na,K-Atpase, Pengfei Liang

USF Tampa Graduate Theses and Dissertations

The Na/K pumps are essential for living system and widely expressed in all eukaryotic cell membranes. By actively transporting sodium ions out of and potassium ions into the plasma membrane, Na/K pumps creates both an electrical and a chemical gradient across the plasma membrane, which are crucial for maintaining membrane potential, cell volume, and secondary active transporting of other solutes, etc.

Previously, oscillating electric field with a frequency close to the mean physiological turnover rate was used to synchronize and modulate the Na/K pump molecules. Results showed that the turnover rate of Na/K pumps can be accelerated by folds. However, …