Biochemistry Commons^™

Processing The Interspecies Quorum-Sensing Signal Autoinducer-2 (Ai-2) Characterization Of Phospho-(S)-4,5-Dihydroxy-2,3-Pentanedione Isomerization By Lsrg Protein, J. C. Marques, P. Lamosa, Caitlin Elizabeth Russell , '11, R. Ventura, C. D. Maycock, M. F. Semmelhack, Stephen T. Miller, K. B. Xavier

Chemistry & Biochemistry Faculty Works

The molecule (S)-4,5-dihydroxy-2,3-pentanedione (DPD) is produced by many different species of bacteria and is the precursor of the signal molecule autoinducer-2 (AI-2). AI-2 mediates interspecies communication and facilitates regulation of bacterial behaviors such as biofilm formation and virulence. A variety of bacterial species have the ability to sequester and process the AI-2 present in their environment, thereby interfering with the cell-cell communication of other bacteria. This process involves the AI-2-regulated lsr operon, comprised of the Lsr transport system that facilitates uptake of the signal, a kinase that phosphorylates the signal to phospho-DPD (P-DPD), and enzymes (like LsrG) that are responsible …

Pcr Amplification Of Trypanosoma Cruzi - Specific Dna From Raccoon Blood Samples, Colin Moss

Mahurin Honors College Capstone Experience/Thesis Projects

The parasitic protist Trypanosoma cruzi is the causative agent of Chagas Disease. Chagas Disease causes greater than 15,000 deaths each year, and nearly 28 million people are believed to be at risk of infection in Central and South America. This parasite has been described in many mammalian host species and has also been described in the United States. The purpose of this study was to attempt to use PCR to amplify T. cruzi-specific DNA directly from blood samples obtained from raccoons (Procyon lotor) trapped in Warren and Barren Counties of Kentucky in 2007 and 2008. DNA was …

A Small Zinc Finger Thylakoid Protein Plays A Role In Maintenance Of Photosystem Ii In Arabidopsis Thaliana, Yan Lu, David Hall, Robert Last

Yan Lu

No abstract provided.

Characterization Of Esterase Activity From The Bacteria, Francisella Tularensis, The Causative Agent Of Tularemia, Leigh Anna Weston

Undergraduate Honors Thesis Collection

Francisella tularensis is the bacteria responsible for causing the disease tularemia and is listed as one of the top three-biowarfare agents. Among the proteins essential to the virulence and infectivity of F.tularensis are multiple esterases, which are enzymes that break down various ester, thioester, and amide bonds. In this project, the catalytic activity, substrate speci fi city, and structure of a putative esterase from F.tularensis was studied. Latent fluorophores based on the molecule, fluorescein, were unmasked by the enzymatic activity of the esterase and the increase in fluorescence was measured over time to determine how well the e tcrase recognized …

Chiral Recognition Study Of A Bimolecular Process In Amino Acid Chiral Ionic Liquids, Laurel Millikan Heckman

Undergraduate Honors Thesis Collection

In this study, chiral ionic liquid (CIL) solvents were prepared and tested for their chiral discrimination ability by probing with luminescence quenching. The CIL's were also tested for their impurities, viscosity and density. These experiments will help to determine the ability of CIL's to act as solvents in asymmetric catalysis. The chiral ionic liquids in this study were composed of amino acid methyl ester cations and bis(trifluoromethane) sulfonimide or bistri flimide anions (i.e. I-alanine methyl ester bistriflimid e, d-alanine methyl ester bistr iflim ide and I-leuci ne methyl ester bistriflimde). Circularly polarized luminescence (CPL) and its quenching in the chiral …

Digeorge Critical Region 8 (Dgcr8) Is A Double-Cysteine-Ligated Heme Protein., Ian Barr, Aaron T. Smith, Rachel Senturia, Yanqiu Chen, Brooke D. Scheidemantle, Judith N. Burstyn, Feng Guo

Natural Sciences and Mathematics | Faculty Scholarship

All known heme-thiolate proteins ligate the heme iron using one cysteine side chain. We previously found that DiGeorge Critical Region 8 (DGCR8), an essential microRNA processing factor, associates with heme of unknown redox state when overexpressed in Escherichia coli. On the basis of the similarity of the 450-nm Soret absorption peak of the DGCR8-heme complex to that of cytochrome P450 containing ferrous heme with CO bound, we identified cysteine 352 as a probable axial ligand in DGCR8. Here we further characterize the DGCR8-heme interaction using biochemical and spectroscopic methods. The DGCR8-heme complex is highly stable, with a half-life exceeding 4 …

Transactivation By Human Adenovirus Early Region 1a-Conserved Region Three, Jailal Ng Ablack

Electronic Thesis and Dissertation Repository

One of the critical functions of human adenovirus (hAd) early region 1A (E1A) protein is to activate transcription of the early viral genes. The largest isoform of E1A contains a unique region termed conserved region 3 (CR3), which includes a Cysteine-4 (C4) zinc finger domain. This region activates viral gene expression by interacting with and recruiting cellular transcription machinery to the regulatory regions of early viral genes. Although this process has been studied at length with hAd type 5 E1A, far less is known about how the E1A proteins from other hAd types activate transcription. There are dramatic differences in …

Antimicrobial And Antioxidant Activities Of Essential Oil And Methanol Extract Of Matricaria Chamomilla L. From Djibouti, Fatouma M. Abdoul-Latif, Mohamed Nabil, Prosper Edou, Adwa A. Ali, Samatar O. Djama, Louis-Clément Obamé, Mamoudou H. Dicko Prof.

Pr. Mamoudou H. DICKO, PhD

The essential oil and methanol extracts of Matricaria Chamomilla L. were subjected to screening for their possible antioxidant activity by two complementary test systems, namely 2,2-diphenykpicrylhydrazyl (DPPH) free radical scavenging and β-carotene-linoleic acid assays. BHT was used as positive control in both test systems. In the DPPH test system, the IC50 values of essential oil and methanol extracts were 4.18 and 1.83 μg/ml, respectively. In the β-carotene-linoleic acid system, oxidation was effectively inhibited by M. Chamomilla, the RAA value of essential oil and methanol extracts were 12.69 and 11.37 %, respectively. When compared to BHT, the essential oil and methanol …

Muc4 Modulation Of Ligand-Independent Erbb2 Signaling, Goldi Attias Kozloski

Goldi A Kozloski

The membrane mucin Muc4 is a heterodimer, bi-functional glycoprotein complex that is normally expressed in epithelial tissue. Functional studies on the extracellular mucin subunit of Muc4 have shown that it acts to promote anti-adhesion properties by sterically interfering with cell-cell and cell-matrix interactions and that the extent of this effect is directly associated with the number of tandem repeats on this subunit. Functional studies on the transmembrane subunit of Muc4 have shown that this subunit participates in intracellular signaling through interaction with the receptor tyrosine kinase ErbB2. This role of Muc4 was shown to be mediated by stabilizing the heregulin …

Hypervirulent Chlamydia Trachomatis Clinical Strain Is A Recombinant Between Lymphogranuloma Venereum (L(2)) And D Lineages, Naraporn Somboonna, Raymond Wan, David M. Ojcius, Matthew A. Pettengill, Sandeep J. Joseph, Alexander Chang, Ray Hsu, Timothy D. Read, Deborah Dean

All Dugoni School of Dentistry Faculty Articles

Chlamydia trachomatis is an obligate intracellular bacterium that causes a diversity of severe and debilitating diseases worldwide. Sporadic and ongoing outbreaks of lymphogranuloma venereum (LGV) strains among men who have sex with men (MSM) support the need for research on virulence factors associated with these organisms. Previous analyses have been limited to single genes or genomes of laboratory-adapted reference strain L₂/434 and outbreak strain L₂b/UCH-1/proctitis. We characterized an unusual LGV strain, termed L₂c, isolated from an MSM with severe hemorrhagic proctitis. L₂c developed nonfusing, grape-like inclusions and a cytotoxic phenotype in culture, …

Understanding The Thermodynamics Of Enzyme-Antibiotic Interactions With Aminoglycoside Phosphotransferase-3’-Iiia, Michele K. Miller

Chancellor’s Honors Program Projects

No abstract provided.

Pollen Myosins And The Specific Role Of Xij, Whitnee Michelle Ferari

Chancellor’s Honors Program Projects

No abstract provided.

A Novel Function For Aurora B Kinase In The Regulation Of P53 By Phosphorylation, Chris P. Gully

Dissertations & Theses (Open Access)

The mitotic kinase Aurora B plays a pivotal role in mitosis and cytokinesis and governs the spindle assembly checkpoint which ensures correct chromosome segregation and normal progression through mitosis. Aurora B is overexpressed in breast and other cancers and may be an important molecular target for chemotherapy. Tumor suppressor p53 is the guardian of the genome and an important negative regulator of the cell cycle. Previously, it was unknown whether Aurora B and p53 had mutual regulation during the cell cycle. A small molecule specific inhibitor of Aurora B, AZD1152, gave us an indication that Aurora B negatively impacted p53 …

Microscopy Techniques For Investigating Interactions In Microbial Systems, Amanda Nicole Edwards

Doctoral Dissertations

Biological interactions occur on multiple length scales, ranging from molecular to population wide interactions. This work describes the study of two specific areas of biological interactions in microbial systems: intracellular protein-protein interactions and cell-to-cell interactions. The implementation of optical and atomic force microscopy and the methodologies developed during this study proved to be invaluable tools for investigating these systems.

Identifying and characterizing protein interactions are fundamental steps toward understanding complex cellular networks. We have developed a unique methodology which combines an imaging-based protein interaction assay with a fluorescence recovery after photobleaching technique (FRAP). Protein interactions are readily detected by co-localization …

Chemical Tools To Characterize Membrane-Protein Binding Interactions Using Synthetic Lipid Probes, Meng Meng Rowland

Doctoral Dissertations

Signaling lipids such as diacylglycerol (DAG) and the phosphatidylinositol polyphosphates (PIP_ns) play crucial roles in numerous cellular pathways. However, characterization of their activities is hindered by the complexity of associated signaling pathways and of the membrane environment. To address this issue, we have developed lipid probes that are effective for characterizing biological events using different applications, including activity-based probing (PIP_ns and DAG) and microarray analysis (PIP_ns). The activity-based probes have been applied to label receptor targets in multiple cancer cell proteomes through photocrosslinking followed by click reactions. The probes were found to label several …

Spatial And Temporal Characterization Of Extracellular Proteases In The Scn, The Mammalian Circadian Clock, Alicia N. Mcclintock

Chancellor’s Honors Program Projects

No abstract provided.

Recombinant Production Of Vitronectin And Insights Into Its Structure And Role In Fibrinolysis, Cameron T. Landers

Chancellor’s Honors Program Projects

No abstract provided.

Stress Effects On Myosin Mutant Root Length In Arabidopsis Thaliana, Brett A. George

Chancellor’s Honors Program Projects

No abstract provided.

Role Of The Extensin Superfamily In Primary Cell Wall Architecture, Derek T.A. Lamport, Marcia J. Kieliszewski, Yuning Chen, Maura Cannon

Maura Cannon

No abstract provided.

Effects Of Ethanol On Social Behavior & Brain Structure, Lua Jafari

Honors Capstone Projects - All

Autism spectrum disorders are a developmental disorder characterized by abnormal social behavior. Those with autism have problems with social interactions, repetitive behaviors, and both verbal and non-verbal communication. While the cause of autism is not yet know, studies have shown that there are both genetic and environmental factors linked with autism. The amygdala is considered to be part of the “social brain”, and atypical activation and morphology of the amygdala has been seen in those with autism.

For this research project, I utilized rats subjected to acute ethanol exposure during gestation and examined exposure effects on the anatomy and biochemistry …