Biochemistry, Biophysics, and Structural Biology Commons^™

Amelioration Of Amyloid Burden In Advanced Human And Mouse Alzheimer's Disease Brains By Oral Delivery Of Myelin Basic Protein Bioencapsulated In Plant Cells, Neha Kohli

Electronic Theses and Dissertations

One of the pathological hallmarks of Alzheimer's disease (AD) is the amyloid plaque deposition in aging brains by aggregation of amyloid-β (Aβ) peptides. In this study, the effect of chloroplast derived myelin basic protein (MBP) fused with cholera toxin subunit B (CTB) was investigated in advanced diseased stage of human and mouse AD brains. The CTB-fusion protein in chloroplasts facilitates transmucosal delivery in the gut by the natural binding ability of CTB pentameric form with GM1 receptors on the intestinal epithelium. Further, bioencapsulation of the MBP within plant cells confers protection from enzymes and acids in the digestive system. Here, …

Identification Of Novel Antimalarial Scaffolds From Marine Natural Products, Bracken Roberts

Electronic Theses and Dissertations

Malaria, the disease caused by Plasmodium sp., claims the lives of over 1 million people every year, with Plasmodium falciparum causing the highest morbidity. Rapidly acquiring drug resistance is threatening to exhaust our antimalarial drug arsenal and already requires the utilization of combination drug therapy in most cases. The global need for novel antimalarial chemical scaffolds has never been greater. Screening of natural product libraries is known to have higher hit rates than synthetic chemical libraries. This elevated hit rate is somewhat attributed to the greater biodiversity available in natural products. Marine life is the most biodiverse system on the …

Light-Activated Binary Nucleotide Reagent For Inactivation Of Dna Polymerase, Evan M. Cornett

Electronic Theses and Dissertations

This work explores a binary reagent approach to increase the specificity of covalent inhibitors. In this approach, two ligand analogs equipped with inert pre-reactive groups specifically bind a target biopolymer. The binding event brings the pre-reactive groups in proximity with each other. The two groups react, generating active chemical intermediates that covalently modify and inactivate the target. In the present study we compare the new approach with the traditional single-component reagent strategy using DNA polymerase from bacteriophage T4 as a model target biopolymer. We report the design and synthesis of two analogs of deoxythymidine triphosphate, a natural DNA polymerase substrate. …

Why Do We Collect?, Allison Marsh

Section 2: Imaging the Microscopic

No abstract provided.

Spotlight On Usc: A.C. Moore Herbarium, Allison Marsh

Section 2: Imaging the Microscopic

No abstract provided.

Imaging And Aesthetics, Allison Marsh

Section 2: Imaging the Microscopic

No abstract provided.

Conclusion Panel, Allison Marsh

Section 6: Conclusion

No abstract provided.

Insights Into Hepatic Alpha-Fetoprotein Gene Regulation During Liver Development And Disease, Erica Leigh Clinkenbeard

Theses and Dissertations--Microbiology, Immunology, and Molecular Genetics

The liver is an essential organ for cholesterol homeostasis. If this process becomes dysregulated, cardiovascular disease (CVD) develops. Zinc-fingers and homeoboxes 2 (Zhx2) as an important hepatic gene regulator and contributes to CVD. BALB/cJ mice, with mutant Zhx2 allele, have fewer atherosclerotic plaques compared to other strains on a high fat diet. In my dissertation, I focused on the liver phenotype in BALB/cJ mice on a high-fat diet and found increased liver damage compared to wild-type Zhx2 mice. These data indicates that reduced Zhx2 in the liver leads to CVD resistance, but increases liver damage. Therefore, Zhx2 has an important …

Role Of Cyclooxygenase-2 In Abdominal Aortic Aneurysms In Mice, Kamalika Mukherjee

Theses and Dissertations--Pharmacy

Abdominal aortic aneurysm (AAA) is a chronic inflammatory disease with no available pharmacological treatment. AAA formation reduces the structural integrity of the vessel and increases the susceptibility to rupture. The inflammatory response within human aneurysmal tissue is characterized by increased expression of cyclooxygenase-2 (COX-2). Similarly, in a mouse model of the disease induced by chronic Angiotensin II (AngII) infusion, we have shown that COX-2 expression in the abdominal aortic smooth muscle layer increases early in the development of the disease. Furthermore, genetic or pharmacological inactivation of COX-2 prior to disease initiation reduces AAA incidence.

The current study utilized nonhyperlipidemic mice …

C6 Pyridinium Ceramide Influences Alternative Pre-Mrna Splicing By Inhibiting Protein Phosphatase-1, Chiranthani Sumanasekera, Olga Kelemen, Monique Beullens, Brandon E. Aubol, Joseph A. Adams, Manjula Sunkara, Andrew J. Morris, Mathieu Bollen, Athena Andreadis, Stefan Stamm

Molecular and Cellular Biochemistry Faculty Publications

Alternative pre-mRNA processing is a central element of eukaryotic gene regulation. The cell frequently alters the use of alternative exons in response to physiological stimuli. Ceramides are lipid-signaling molecules composed of sphingosine and a fatty acid. Previously, water-insoluble ceramides were shown to change alternative splicing and decrease SR-protein phosphorylation by activating protein phosphatase-1 (PP1). To gain further mechanistical insight into ceramide-mediated alternative splicing, we analyzed the effect of C6 pyridinium ceramide (PyrCer) on alternative splice site selection. PyrCer is a water-soluble ceramide analog that is under investigation as a cancer drug. We found that PyrCer binds to the PP1 catalytic …

Non-Canonical Roles For Stat1 And Stat2 In Mitochondrial Biogenesis And Fasting Homeostasis., Jennifer Sisler

Theses and Dissertations

The signal transducer and activator of transcription 1 (STAT1) and 2 (STAT2) are primarily activated by interferons and play a central role in orchestrating responses to a variety of pathogens by activating the transcription of nuclear encoded genes that mediate antiviral, antigrowth and immune surveillance responses. In addition to their nuclear effects, we report that STAT1 and STAT2 inhibit the expression of mitochondrial encoded mRNAs by activating type I interferons (IFNβ) under basal conditions. STAT1-/- livers also exhibit elevated levels of nuclear encoded components of the electron transport chain (ETC). Treatment of wild-type mice with IFNβ inhibits both mitochondrial and …

Genetic Control Of A Central Pattern Generator: Rhythmic Oromotor Movement In Mice Is Controlled By A Major Locus Near Atp1a2, Steven J. St. John, John D. Boughter Jr, Megan K. Mulligan, Kenichi Tokita, Lu Lu, Detlef H. Heck, Robert W. Williams

Faculty Publications

calreticulin, Animals, Chromosome Mapping, Mammalian Chromosomes, Gene Expression Regulation, Genetic Linkage, Genome-Wide Association Study. Inbred C57BL Mice, Inbred DBA Mice, Quantitative Trait Loci, Sodium-Potassium-Exchanging ATPase/genetics, Atp1a2 protein, Sodium-Potassium-Exchanging ATPase, feeding behavior, drinking behavior, mice, central pattern generator, genetic control

Cell Cycle Arrest Associated With Anoxia-Induced Quiescence, Anoxic Preconditioning, And Embryonic Diapause In Embryos Of The Annual Killifish Austrofundulus Limnaeus, Camie Lynn Meller, Robert Meller, Roger P. Simon, Kristin M. Culpepper, Jason E. Podrabsky

Biology Faculty Publications and Presentations

Embryos of the annual killifish Austrofundulus limnaeus can enter into dormancy associated with diapause and anoxia-induced quiescence. Dormant embryos are composed primarily of cells arrested in the G1/G0 phase of the cell cycle based on flow cytometry analysis of DNA content. In fact, most cells in developing embryos contain only a diploid complement of DNA, with very few cells found in the S, G2, or M phases of the cell cycle. Diapause II embryos appear to be in a G0-like state with low levels of cyclin D1 and p53. However, the active form of pAKT is high during diapause II. …

Microfluidic Impedance Spectroscopy As A Tool For Quantitative Biology And Biotechnology, Ahmet C. Sabuncu, Jie Zhuang, Juergen F. Kolb, Ali Beskok

Mechanical & Aerospace Engineering Faculty Publications

A microfluidic device that is able to perform dielectric spectroscopy is developed. The device consists of a measurement chamber that is 250 μm thick and 750 μm radius. Around 1000 cells fit inside the chamber assuming average quantities for cell radius and volume fraction. This number is about 1000 folds lower than the capacity of conventional fixtures. A T-cell leukemia cell line Jurkat is tested using the microfluidic device. Measurements of deionized water and salt solutions are utilized to determine parasitic effects and geometric capacitance of the device. Physical models, including Maxwell-Wagner mixture and double shell models, are used to …

Microfluidic Separation Of Live And Dead Yeast Cells Using Reservoir-Based Dielectrophoresis, Saurin Patel, Daniel Showers, Pallavi Vedantam, Tzuen-Rong Tzeng, Shizhi Qian, Xiangchun Xuan

Mechanical & Aerospace Engineering Faculty Publications

Separating live and dead cells is critical to the diagnosis of early stage diseases and to the efficacy test of drug screening, etc. This work demonstrates a novel microfluidic approach to dielectrophoretic separation of yeast cells by viability. It exploits the cell dielectrophoresis that is induced by the inherent electric field gradient at the reservoir-microchannel junction to selectively trap dead yeast cells and continuously separate them from live ones right inside the reservoir. This approach is therefore termed reservoir-based dielectrophoresis (rDEP). It has unique advantages as compared to existing dielectrophoretic approaches such as the occupation of zero channel space and …

Protein Structure Networks, Lesley H. Greene

Chemistry & Biochemistry Faculty Publications

The application of the field of network science to the scientific disciplines of structural biology and biochemistry, have yielded important new insights into the nature and determinants of protein structures, function, dynamics and the folding process. Advancements in further understanding protein relationships through network science have also reshaped the way we view the connectivity of proteins in the protein universe. The canonical hierarchical classification can now be visualized for example, as a protein fold continuum. This review will survey several key advances in the expanding area of research being conducted to study protein structures and folding using network approaches.

Expansion Dating: Calibrating Molecular Clocks In Marine Species From Expansions Onto The Sunda Shelf Following The Last Glacial Maximum, Eric D. Crandall, Elizabeth J. Sbrocco, Timery S. Deboer, Paul H. Barber, Kent E. Carpenter

Biological Sciences Faculty Publications

The rate of change in DNA is an important parameter for understanding molecular evolution and hence for inferences drawn from studies of phylogeography and phylogenetics. Most rate calibrations for mitochondrial coding regions in marine species have been made from divergence dating for fossils and vicariant events older than 1-2 My and are typically 0.5-2% per lineage per million years. Recently, calibrations made with ancient DNA (aDNA) from younger dates have yielded faster rates, suggesting that estimates of the molecular rate of change depend on the time of calibration, decaying from the instantaneous mutation rate to the phylogenetic substitution rate. aDNA …

Protein Folding By 'Levels Of Separation': A Hypothesis, Lesley H. Greene, Terri M. Grant

Chemistry & Biochemistry Faculty Publications

The protein folding process has been studied both computationally and experimentally for over 30 years. To date there is no detailed mechanism to explain the formation of long-range interactions between the transition and native states. Long-range interactions are the principle determinants of the tertiary structure. We present a theoretical model which proposes a mechanism for the acquisition of these interactions as they form in a modified version of ‘degrees of separation’, that we term ‘levels of separation’. It is based on the integration of network science and biochemistry. (C) 2012 Federation of European Biochemical Societies.

Further Characterization Of The Nodamura Virus Rna2 3'-Terminal Stem Loop Structure And Its Role In Viral Rna Replication, Joshua Frederick

Open Access Theses & Dissertations

Nodamura virus (NoV) is an excellent model system for studying many aspects of the life cycle of positive-strand RNA viruses. NoV's simple genome organization and ability to replicate its genome to high levels in a wide variety of host cells, including plants, yeast, insects and mammals (Ball et al., 1992; Garzon et al., 1978, 1990; Murphy et al., 1970; Price et al., 2005; Scherer & Hurlbut, 1967; Selling et al., 1990; reviewed by Ball & Johnson, 1998), make it a prime model system for studying the basic mechanisms of viral RNA replication. Other positive-strand RNA viruses, including those that are …

The Effects Of Extended Access To Methamphetamine Self-Administration On Dopaminergic Markers In The Striatum, Joe Luevano

Open Access Theses & Dissertations

Methamphetamine (METH) abuse is a persistent problem in the U.S. and abroad. Escalation of METH use among independent users occurs for a variety of physiological and psychological reasons. Methamphetamine dependence may be attributed to the rewarding effect of this drug via the dopaminergic systems of the central nervous system (CNS). The presence of METH in the CNS increases synaptic release of dopamine. This increase in dopaminergic neurotransmission is thought to be directly attributed to the rewarding effects of METH. Following METH use, compensatory changes have been found to occur in the dopaminergic system during various periods of abstinence. It is …