Chemistry Commons^™

Selenium Probes For The Detection Of Thioredoxin Reductase Activity, Tendai Joseph Mafireyi

Dissertations and Theses

The identification and quantification of proteins and enzymatic activity in living tissues frequently requires the use of invasive procedures such as biopsy. These techniques can inhibit measurements of protein levels in real-time, and the disruption of tissue can lead to the loss of important information concerning the spatial distribution and differential activities in various cell types. The use of small organic fluorescent probes that rely on activation or accumulation within a tissue embody robust methods of detection that address these issues. This dissertation describes the design, synthesis and evaluation of fluorescent probes that can detect the enzyme thioredoxin reductase (TrxR). …

Connecting Chemistry To Community With Deliberative Democracy, Regis Komperda, Jack Barbera, Erin Shortlidge, Gwen Shusterman, Stem Education And Equity Institute, Portland State University

Biology Faculty Publications and Presentations

Science education communities have called for rethinking curricula to improve student understanding of the nature of science and the role of science in addressing controversial modern issues such as climate change, energy policy, and pollution levels. One approach to meeting this call is integrating these topics into class activities that require students to use discussion and scientific approaches to solve problems and deliberate potential policy solutions. Deliberative democracy (DD) is one such active learning approach in which students work in peer groups to reach a consensus on a scientific topic relevant to both real-world issues and course content. During DD …

Empirical Demonstration Of Environmental Sensing In Catalytic Rna: Evolution Of Interpretive Behavior At The Origins Of Life, Niles Lehman, Tess Bernhard, Brian C. Larson, Andrew J.N. Robinson, Christopher C.B. Southgate

Chemistry Faculty Publications and Presentations

Background: The origins of life on the Earth required chemical entities to interact with their environments in ways that could respond to natural selection. The concept of interpretation, where biotic entities use signs in their environment as proxy for the existence of other items of selective value in their environment, has been proposed on theoretical grounds to be relevant to the origins and early evolution of life. However this concept has not been demonstrated empirically.

Results: Here, we present data that certain catalytic RNA sequences have properties that would enable interpretation of divalent cation levels in their environment. …

An Embarrassment Of Riches: The Enzymology Of Rna Modification, Dirk Iwata-Reuyl

Chemistry Faculty Publications and Presentations

The maturation of transfer RNA (tRNA) involves extensive chemical modification of the constituent nucleosides and results in the introduction of significant chemical diversity to tRNA. Many of the pathways to these modified nucleosides are characterized by chemically complex transformations, some of which are unprecedented in other areas of biology. To illustrate the scope of the field, recent progress in understanding the enzymology leading to the formation of two distinct classes of modified nucleosides, the thiouridines and queuosine, a 7-deazaguanosine, is reviewed. In particular, recent data validating the involvement of several proposed intermediates in the formation of thiouridines are discussed, including …

The Subsystems Approach To Genome Annotation And Its Use In The Project To Annotate 1000 Genomes, Ross Overbeek, Tadhg Begley, Ralph M. Butler, Jomuna V. Choudhuri, Han-Yu Chuang, Matthew Cohoon, Valérie De Crécy-Lagard, Naryttza Diaz, Terry Disz, Robert Edwards, Michael Fonstein, Ed D. Frank, Svetlana Gerdes, Elizabeth M. Glass, Alexander Goesmann, Andrew Hanson, Dirk Iwata-Reuyl, Roy Jensen, Neema Jamshidi, Lutz Krause, Michael Kubal, Niels Larsen, Burkhard Linke, Alice C. Mchardy, Folker Meyer, Heiko Neuweger, Gary Olsen, Robert Olson, Andrei Osterman, Vasiliy Portnoy, Gordon D. Pusch, Dmitry A. Rodionov, Christian Rückert, Jason Steiner, Rick Stevens, Ines Thiele, Olga Vassieva, Yuzhen Ye, Olga Zagnitko, Veronika Vonstein

Chemistry Faculty Publications and Presentations

The release of the 1000^th complete microbial genome will occur in the next two to three years. In anticipation of this milestone, the Fellowship for Interpretation of Genomes (FIG) launched the Project to Annotate 1000 Genomes. The project is built around the principle that the key to improved accuracy in high through put annotation technology is to have experts annotate single subsystems over the complete collection of genomes, rather than having an annotation expert attempt to annotate all of the genes in a single genome. Using the subsystems approach, all of the genes implementing the subsystem are analyzed by …

The Combined Effect Of Cu And Zn On Selenastrum Capricornutum, Helmer Colonia-Roque

Dissertations and Theses

It has been demonstrated that the toxicity of heavy metals depends on their chemical speciation and can be related to their free ion activities, rather than the total metal concentrations. The objective of this study was to determine the effect of combined free ions of zinc and copper on the toxicity to the green alga Selenastrum capricornutum. This alga was grown in a defined medium, under controlled laboratory conditions, with a varying range of zinc and copper concentrations. The growth rate of the alga was inhibited at pZn = 5.93 or at pCu = 7.24. The results suggest that …