Tag: Poster 69

Development of a Pull-down Procedure for Isolating Platinated Cellular Molecules

Presenter: Anna Hickey

Faculty Mentor: Victoria DeRose, Geri Richmond

Presentation Type: Poster 69

Primary Research Area: Science

Major: Biochemistry

Funding Source: Presidential Undergraduate Research Scholars Program, University of Oregon, $5,000.00 research stipend; Scholarships for Oregon Scientists, University of Oregon and National Science Foundation, $2,000.00 research stipend

Cisplatin is a commonly used anti-cancer therapeutic; however, its mechanism of inducing cell death is not well understood. In order to identify and isolate cisplatin’s cellular targets for characterization, our lab utilizes the
“click” reaction (a physiologically stable and high yielding reaction that produces no harmful byproducts) to attach fluorescent compounds or other small molecules to platinated cellular targets such as DNA, RNA, and proteins. In this project, I optimized an in vitro pull-down procedure using streptavidin-coated magnetic beads to separate platinated cellular targets from unplatinated molecules. I first treated target DNA with a click-functionalized platinum reagent, then clicked that compound to a double-stranded DNA linker. The opposite end of this linker contains a biotin molecule, which interacts strongly with the streptavidin-coated magnetic beads through the streptavidin-biotin interaction. Using a powerful magnet, I separated platinated and clicked DNA attached to the beads from unreacted DNA, then confirmed the desired species of DNA was pulled down using polyacrylamide gel electrophoresis (PAGE), a method by which DNA or proteins can be separated by size. I determined that increasing the incubation time of the beads with the platinated DNA increased elution yields. Furthermore, elution temperatures above 90° C also increase the elution yield. Optimizing this pull-down technology will allow us to better characterize platinated molecules, and will ultimately improve our understanding of cisplatin’s cell-death inducing mechanisms.

Synthesis of Alkyne Substituted Cycloparaphenylenes for Conjugated Polymers

Presenter(s): William Edgell − Biochemistry

Faculty Mentor(s): Ramesh Jasti

Poster 69

Research Area: Organic Synthetic Chemistry

Funding: Undergraduate Research Opportunities Program (UROP)

Conjugated polymers possess excellent conductive properties that could facilitate the construction of light weight flexible electronics. This potential application makes an efficient route to conjugated polymers synthetically desirable. The current barrier to large-scale synthesis of these molecules is an inversely proportional relationship between solubility and conductivity. The sought-after conductivity is due to charge transfer across a conjugated π system within the polymer. This affords the polymers with electronic properties atypical of organic molecules. Unfortunately, intermolecular stacking of these π systems leads to poor solubility. Cycloparaphenylenes(CPPs) offer a solution for this conflict between solubility and charge transfer. CPPs are large hoops of strained benzene rings which possess a conjugated π system without a clear avenue for π stacking. A CPP polymer would form a sort of molecular necklace; with large bulky hoops hanging off the polymer backbone, the potential polymers would not stack well with each other, thus reducing chance of aggregation. Utilization of the CPPs as monomers for polymer synthesis could produce a polymer chain with the ideal electrical properties without diminishing the solubility. To this end, this research project focuses on the synthesis of the CPP monomers to be used for the polymer reaction. Creating this highly strained hoop requires a series of reactions to form a string of benzene rings that will be coupled to a single alkyne functionalized benzene. Previous work shows challenges in the route that yields the eight ring CPP. Current work has yielded successful synthesis of functionalized six ring cycloparaphenylene.

Determining the differential contributions of thalamic nuclei in visual processing

Presenter(s): Alyssa Fuentez

Faculty Mentor(s): Angie Michaiel & Cris Niell

Poster 69

Session: Sciences

Visual processing is a vital sense that allows us to interact with the world, yet the mechanisms behind this process remain unknown. Previous research has demonstrated that the thalamus, a midbrain structure, actively regulates information communication to the visual cortex, an area at which attention and decision making occurs. The thalamus is divided into multiple cells called nuclei where first-order nuclei are thought to relay direct sensory information from the outside world to primary cortical areas; whereas, higher-order nuclei are thought to be involved in contextual processing and sensory feedback to higher-order cortical areas. Although research has shown that primary and higher-order thalamic nuclei are involved in visual processing, it has yet to be determined their differential contributions to visual processing. We examined this question by temporarily inactivating primary and higher-order thalamic nuclei separately in six transgenic adult mice that express a fluorescent indicator of neural activity. Visual stimuli were presented and neural activity was monitored using calcium imaging pre and post thalamic nuclei inhibition. Results demonstrated that inhibition of primary thalamic nuclei leads to a minimal increase in visual cortical activity (n=1); whereas, inhibition of higher-order thalamic nuclei resulted in a decrease of both the magnitude and spread of activity (n=1). Results are considered inconclusive due to mistargeting of viral expression observed in four subjects. Additional experiments targeting thalamic nuclei separately are in progress to obtain conclusive results. These studies will lay the foundation for future studies regarding the differential roles of thalamic nuclei in regulating visually guided behaviors.