Category Archives: poster

Guo-Hsuen Lo–Engineering a photosynthetic yeast through endosymbiosis

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Abstract: “Plants and algae conduct photosynthesis through chloroplasts, organelles descended from ancient endosymbiotic cyanobacteria. Despite the fundamental importance of endosymbiosis to the evolution of the eukaryotic cell, we have little practical understanding of how a bacterium was converted into an organelle. I am investigating the early stages of this endosymbiotic event in a laboratory setting by engineering eukaryote/prokaryote chimeras. This can be done by fusing a genetically tractable cyanobacterium with a model yeast cell to generate an endosymbiotic cyanobacterium which can survive and divide within the yeast cytosol. In this system, an auxotrophic cyanobacterium is inserted into a respiration-deficient yeast cell where it provides ATP and/or assimilated carbon (e.g. glucose) generated by photosynthesis. In return, the yeast cytosol provides an essential metabolite to the cyanobacterium. We have observed that mutant cyanobacteria can survive within yeast for multiple generations and can be engineered to enhance growth and longevity of the chimeras. I envision that the existing model may be further optimized to perform many downstream functions, including i) secretion of photosynthetic end-products, ii) host/symbiont protein exchange and iii) genome minimization and evolutionary studies.”

Engineering a photosynthetic yeast through endosymbiosis – transcript

Juan Canchola–Synthesis and Biological Evaluation of the Anaephene Natural Products

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Abstract: “When antibiotics were introduced in the early twentieth century, they were very effective in treating bacterial infections. However, due to bacterial evolution, misuse and overreliance, these primary antibiotics are becoming less effective. Antibiotic resistance is becoming a major global issue, forcing us to question the stability of our pathogenic defenses. Natural products play a critical role in the development of new antibiotics and provide molecular templates for developing novel classes. Anaephenes A, B, and C are series of alkylphenols, that have shown to be effective antibiotics against Bacillus cereus and Staphylococcus aureus. They were isolated from a marine bacterium off the coast of Guam, known as Hormoscilla oscillatoriales. We have successfully synthesized anaephenes A and B, both which have never been synthesized before. We have confirmed the structure of these molecules using spectroscopic techniques such as 1H and 13C NMR, HMBC, HSQC, and COSY spectra. We have also confirmed their biological activity. Additionally, Anaephenes A and B displayed antimicrobial activity against methicillin-resistant Staphylococcus aureus (MRSA) with MIC values of 16 and 8 ug/mL, respectively.”

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Cody Busch–Antimicrobial properties of silver nanoparticle-impregnated wheat gluten biofilms

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Abstract: “Wheat gluten (WG) biofilms result in a more affordable and biodegradable alternative for medical first aid bandages. WG biofilms were prepared by denaturing the WG protein with acid and heat, mixing with glycerol, and then drying to remove excess liquid. WG film properties such as density and porosity were measured. Different concentrations of silver nanoparticles (AgNPs) were synthesized and incorporated into the WG films to test their antimicrobial properties using several different pathogens. It was concluded that as the concentration of silver decreases, the diameter of the zone of inhibition also decreases, conveying that higher amounts of silver exhibit stronger antimicrobial properties. Incorporation of silver nanoparticles into WG biofilms had weaker antimicrobial properties than the silver disks alone. Some pathogens such as Klebsiella pneumoniae were more susceptible to the antimicrobial properties of WG with 0% AgNPs than WG with 100% AgNPs.”

ECI Abstract Manuscript

Namuunzul Otgontseren–Accessing In Vivo and Multiplexed Imaging through the Development of a Multicolor Panel of Activatable HNO Probes

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Abstract: “Nitroxyl (HNO) is the one-electron reduced form of nitric oxide, a compound whose high reactivity makes it difficult to study. Previously, we developed NitroxylFluor, a fluorescent probe suitable for live-cell fluorescence imaging of HNO. This project aims to create derivatives of NitroxylFluor to optimize its localization, spectral properties, and photophysical properties. The proposed three congeners will be red-shifted as we replace the endocyclic oxygen of the xanthene chromophore with a quaternary carbon, dimethylsilicon, and a sulfonyl group. These probes will allow for multiplexed imaging with other probes, fluorescent proteins, or other labels to see interaction between HNO and other analytes and targets. With longer wavelength emissions from these derivatives, there will be reduced light scattering allowing deeper tissue penetration for in vivo imaging. With organelle directing groups, these probes will also give us a greater understanding of where HNO is produced at the subcellular level.”

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Connor Glenn–The Syntheses of Heteroatom-Activated Antibiotics

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Abstract: “Since their discovery and subsequent proliferation in the 1920s, β-lactam antibiotics have contributed to the 50% increase in life expectance over the last century. However, antibiotic overuse and misuse, coupled with the rise in antibiotic resistant pathogens have caused the effectiveness of these drugs to decrease. Oxamazins are a class of heteroatom-activated β-lactam antibiotics that show good broad-spectrum antibiotic. The goal of our research is to progress through a traditional synthesis of simple oxamazins from readily available amino acids. We hope to explore the use of various synthetic strategies to make fully elaborated antibiotic compounds.”

Niya Mitchell–Design and Modeling of Macrocyclic RNA Targeting Agents for DM1

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Abstract: “Myotonic-Dystrophy Type 1 (DM1) is a disease caused by the sequestration of splicing proteins, such as muscleblind-like 1 (MBNL1). The goal of this project is to find molecules that bind to RNA and inhibit MBNL protein sequestration. We used Myotonic-Dystrophy Type 1 (DM1) as a model system. I modeled a series of macrocyclic ligands in Molecular Operating Environment (MOE) using melamine or diaminopurine as a U-U mismatch recognition unit to target r(CUG)exp. The linker length of the ligands was varied to create stable macrocycles with promising hydrogen bonding. The results of these simulations can be coupled with experimental data to better our understanding of DM1 and ligand-RNA interactions.”

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Paul Grocki–Chemometric Analysis of Urinary Volatile Organic Compounds Discriminates Murine Breast Cancer Presence and Progression Over Time

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Abstract: “Previous studies demonstrated that volatile organic compounds (VOCs) in urine are potential biomarkers of breast cancer. An unanswered question is how urinary VOCs change over the course of tumor progression. To explore this, urine samples were collected from female Balb/c mice injected with 4T1.2 murine tumor cells in the tibia prior to tumor injection (20 samples) and over the next three weeks (12, 15, and 18 samples collected during weeks 1, 2, and 3 respectively). Samples were analyzed by headspace solid phase microextraction coupled to GC-MS QTOF. Univariate analysis showed many VOCs dysregulated by cancer, with some varying significantly during cancer progression and others not. PCA using panels of VOCs could distinguish both Cancer Weeks 1-3 from Control and Cancer Week 1 from Cancer Week 3 with > 90% sensitivity and specificity. Forward feature selection and linear discriminant analysis identified a unique panel of five VOCs that could distinguish Cancer Weeks 1 and 3 from Control with a fivefold cross validated (CV) area under the receiver operator characteristic (AUROC) equal to 0.95. The same model could also distinguish Cancer Week 1 from Cancer Week 3 with a fivefold CV AUROC equal to 0.97. The results of this study show that VOCs can be used to monitor breast cancer progression in mice models.

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Thy Nguyen–Donor-Acceptor Characterization of Homoleptic Cobalt Dithione Complexes

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Abstract: “Metallodithiolene complexes are well known for their charge transfer properties that great promise towards the development of material science due to the non-innocent nature of the dithiolene ligand. Dithione (Dt0) ligands exhibit significant charge delocalization across their thioamide moiety, making them redox-active ligands. The ability for Dt0 ligands to participate in redox processes, in conjunction with transition metalcore, grants such complexes potential access to additional redox states. In this project, octahedral cobalt Dt0 complexes, [Co(Me2 Dt0)3][PF6]3 (1) and [Co(iPr2 Dt0)3][PF6]3, (2) have been thoroughly characterized utilizing elemental analysis, mass spectroscopy, IR, UV-Vis, NMR, cyclic voltammetry, and DFT calculations. The excited state transitions of 1 and 2 were determined with TD-DFT calculations and visualized using electronic density difference maps (EDDMs). Low energy charge transfers for 1 and 2 are determined to be MLCT, while higher energy transitions are assigned as Dt0-based p → p* LL’CT.”

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Ryan Baker–Computational Adsorption Dynamics of Halogenated Disinfection Byproducts on Graphenic Surface

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Abstract: “Modern wastewater treatment procedure often results in the creation of halogenated methanes and other disinfection byproducts (DBP). Many of these, namely chloroform and dichloromethane, are known carcinogens, and their removal from municipal water supply is paramount to public safety. Many techniques have been developed to combat this issue, such as the widespread use of activated carbon as an adsorbent. This method is effective, but the nature of the adsorptive interaction is largely understudied. In this study, the adsorption of all chlorine, bromine, and iodine derivatives of methane to a model graphenic structure, circumcoronene, are studied relative to unaltered methane. This adsorption was studied computationally, considering potential starting and final conformers to approximate realistic adsorption at standard temperature.”

Text Transcript_Baker

Kylie Smith–Inorganic Chemistry Lab Development: Iron Solubility

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Abstract: “The electronic configuration and chemistry of iron allows for a variety of coordination compounds and complexes to be formed. These complexes consist of the metal ion bound to ligands, which can be nonmetal ions, small molecules such as H2O, NH3, or large molecules including organic ligands. Metal complexes are important to the function of proteins. For example, heme is a coordination complex of an iron ion coordinated to a porphyrin. Heme is a precursor to hemoglobin which can bind oxygen in the blood. Another example is nitrogenase, an enzyme in cyanobacteria that is important in nitrogen fixation. We are developing an inorganic chemistry lab experiment that introduces students to the coordination chemistry of iron by allowing them to relate complex formation to color changes and solubility. The objectives of the experiments presented here are: i) Observe and understand the chemistry of transition metal complexes. ii) Correctly calculate and prepare solutions of known concentrations. iii) Determine and explain changes in color and solubility in terms of metal-ligand interactions. iv) Analyze metal-ligand formation and generate evidence-supported conclusions. Students explore several concepts related to transition metal chemistry, coordination chemistry, oxidation-reduction reactions, and solubility.”

 

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