Life Sciences Commons^™

Pharmacological Antagonism And The Olfactory Code, Mihwa Na

Dissertations, Theses, and Capstone Projects

Mammals can detect and discriminate uncountable odors through their odorant receptors. To accommodate the countless and diverse odors, exceptionally large numbers of odorant receptor (OR) genes are expressed in mammals. In addition, the mammals utilize a combinatorial code, where an odorant molecule can activate multiple ORs; an OR also responds to a set of multiple odorants. In nature, an odor is often a complex mixture of multiple odorant molecules. The combination of the ORs activated by each constituent generates the unique olfactory code for the particular odor.

Some odorants can antagonize select ORs, as discussed in Chapter 1. An antagonist …

Regulation Of The Amyloid Precursor Protein By Prostaglandin J2, A Mediator Of Inflammation: Relevance To Alzheimer’S Disease, Teneka L. Jean-Louis

Dissertations, Theses, and Capstone Projects

Inflammation plays a major role in Alzheimer’s disease (AD). Investigating how specific mediators of inflammation contribute to neurodegeneration in AD is crucial. Our studies focused on cyclooxygenases, which are key enzymes in inflammation and highly relevant to AD. Cyclooxygenases (COX -1, constitutive; COX-2, inducible) have emerged as important determinants of AD pathogenesis and progression. COX-2 is highly induced in AD, correlating with AD severity, and COX-1 is also involved in AD. Cyclooxygenases are the rate-limiting enzymes that convert arachidonic acid into prostaglandins (PGs), the principal mediators of CNS neuroinflammation.

The overall GOAL of these studies was to address the mechanisms …

Insight Into The Interaction Between The Peroxisome Proliferator-Activated Receptor Gamma (Pparγ) And Adipocyte Fatty Acid-Binding Protein (A-Fabp), Qian Wang

Dissertations, Theses, and Capstone Projects

The Adipocyte Fatty Acid-Binding Protein (AFABP) is mainly expressed in fat cells. It can bind fatty acids and other lipophilic substances such as eicosanoids and retinoids. The peroxisome proliferator-activated receptor γ (PPARγ) is a nuclear receptor protein that requires ligand binding to regulate the specific gene transcription. PPARγ is expressed at extremely high levels in adipose tissue, macrophages, and the large intestine, where it controls lipid adipogenesis and energy conversion. Moreover, it has been found that AFABP and PPARγ can form a complex in vivo. It is proposed that AFABP carries the ligand and enters into the nucleus where it …

Mutagenesis Of Human Alpha-Galactosidase A For The Treatment Of Fabry Disease, Erin Stokes

Dissertations, Theses, and Capstone Projects

Fabry disease is an X-linked lysosomal storage disorder caused by the deficiency of the enzyme, α-galactosidase A, which results in the accumulation of the lipid substrate. This accumulation results in obstruction of blood flow in patients and early demise at approximately 40-60 years of age. There is currently only one FDA approved treatment (Fabrazyme) classified as an enzyme replacement therapy. However, approximately 88% of patients experience a severe immune response that, rarely, can be fatal and is a huge cost burden at average $250,000 a year per patient. The structure of α-galactosidase A has been previously determined to be a …

Potential Modifications To Enzyme Replacement Therapy In Anderson-Fabry Disease, Mariam Meghdari

Dissertations, Theses, and Capstone Projects

Mutations in the GLA gene that encodes the lysosomal enzyme α-galactosidase A (αGal) result in the sphingolipidoses named Fabry disease. This enzymatic defect is inherited as an X-linked recessive disorder and is associated with a progressive deposition of glycosphingolipids, including globotriaosylceramide (GB3), galabioasylceramide, and blood group B substance in the cell. In affected males, and in some females, this leads to early death due to occlusive disease of the heart, kidney, and brain. This disease is currently treated by infusions of αGal, prolonging patients’ lives but producing antibodies against the enzyme reducing the treatment efficacy. Treatment also causes numerous and …

Thermodynamic And Kinetic Analyses Of Iron Response Element (Ire)-Mrna Binding To Iron Regulatory Protein, Irp1, Mateen A. Khan, William E. Walden, Elizabeth C. Theil, Dixie J. Goss

Publications and Research

Comparison of kinetic and thermodynamic properties of IRP1 (iron regulatory protein1) binding to FRT (ferritin) and ACO2 (aconitase2) IRE-RNAs, with or without Mn2+, revealed differences specific to each IRE-RNA. Conserved among animal mRNAs, IRE-RNA structures are noncoding and bind Fe2+ to regulate biosynthesis rates of the encoded, iron homeostatic proteins. IRP1 protein binds IRERNA, inhibiting mRNA activity; Fe2+ decreases IRE-mRNA/IRP1 binding, increasing encoded protein synthesis. Here, we observed heat, 5 °C to 30 °C, increased IRP1 binding to IRE-RNA 4-fold (FRT IRE-RNA) or 3-fold (ACO2 IRE-RNA), which was enthalpy driven and entropy favorable. Mn2+ (50 μM, 25 °C) increased IRE-RNA/IRP1 …

Estrogen-Activated Mdm2 Disrupts Mammary Tissue Architecture Through A P53-Independent Pathway, Nandini Kundu, Angelika Brekman, Jun Yeob Kim, Gu Xiano, Chong Gao, Jill Bargonetti

Publications and Research

The Cancer Genome Atlas (TCGA) data indicate that high MDM2 expression correlates with all subtypes of breast cancer. Overexpression of MDM2 drives breast oncogenesis in the presence of wild-type or mutant p53 (mtp53). Importantly, estrogen-receptor positive (ER+) breast cancers overexpress MDM2 and estrogen mediates this expression. We previously demonstrated that this estrogen-MDM2 axis activates the proliferation of breast cancer cell lines T47D (mtp53 L194F) and MCF7 (wild-type p53) in a manner independent of increased degradation of wildtype p53 (ie, p53-independently). Herein we present data supporting the role of the estrogen-MDM2 axis in regulating cell proliferation and mammary tissue architecture of …

Lipid Sensing By Mammalian Target Of Rapamycin, Deepak Menon

Dissertations, Theses, and Capstone Projects

Mammalian target of Rapamycin (mTOR) is a protein kinase that integrates nutrient and growth factor signals to promote cellular growth and proliferation. mTOR exists in two complexes - mTORC1 and mTORC2 that are distinguished by their binding partners and signaling inputs. mTORC1 is responsive to growth factors, amino acids and glucose and is associated with Raptor; whereas, mTORC2 is responsive primarily to growth factors and is associated with Rictor. Raptor and Rictor confer substrate specificity to mTORC1 and mTORC2 respectively. Phosphatidic acid (PA), a lipid second messenger and a central metabolite for membrane phospholipid biosynthesis, is required for the stability …

Chloride And Proton Binding In The E. Coli 2cl¯:1h+ Clc Exchanger, Catherine Chenal

Dissertations, Theses, and Capstone Projects

The CLC family of membrane proteins is a ubiquitously expressed class of proton and usually voltage-activated chloride transporters involved in a myriad of physiological functions. Crystallographic structures identify up to three chloride binding sites: external, central and intracellular located in the inner half of the trans-membrane domain. The CLC proteins, except for the kidney isoforms, are gated by the extracellular side-facing gating Glutamate (Ex, E148 in CLC-ec1, the E. coli exchanger), which is thought to undergo a conformational change upon protonation.

To sort out how the thermodynamic paths to H+ coupled Cl¯ binding and conformational change in CLC-ec1 at the …

Therapeutic Exploitation Of Metabolic Checkpoints In Cancer Cells, Deven S. Patel

Dissertations, Theses, and Capstone Projects

During the G1 phase of the cell cycle, normal cells respond to growth factors and nutrients prior to entering S-phase to replicate its genome. We previously reported that the growth factor-mediated restriction point is distinguishable from a series of late G1 metabolic checkpoints mediated by essential amino acids (EAAs), the conditionally essential amino acid glutamine (Gln), and mTOR – the mammalian target of rapamycin. Mutations in genes encoding proteins that regulate G1 cell cycle progression are observed in virtually all cancers. We observed that cancer cells with K-Ras mutations bypass the late G1 Gln checkpoint when deprived of Gln and …

Enzymatically Active Microspheres For Self-Propelled Colloidal Engines, Jungeun Park

Dissertations and Theses

Micro- and nano-motors have attracted numerous attentions from various scientific areas due to their potential applications. Most studies on self-propelled colloidal engines have exploited catalytic decomposition of hydrogen peroxide to drive the motor. Since the hydrogen peroxide is caustic, it is not suitable to use in biological applications, encouraging people to develop “greener” fuels. The aim of this research is to study a new transduction mechanism for self-propulsion not tied to hydrogen peroxide, and which can in particular be used with biological molecules as fuels. In this study, we focus on making particles with enzymatic activity which can effectively decompose …