Summer Research 2008

Andrea Tremaine - mentor: Michael Everest

Andrea Cathers 

Title: Immobilization of Polyoxometalates on Functionalized Silica

Polyoxometalates are unique compounds widely used for catalysis and have also been found to be beneficial in some fuel cell systems.  Many of these applications already involve or could benefit from immobilizing the catalyst molecules on an inert substrate such as silica.  Using evanescent-wave cavity ring-down spectroscopy we determined that these molecules do not adsorb to a clean silica surface, but readily adsorb to a surface that has been modified with an organic linker molecule.  Specifically, 3-aminopropyl trimethoxysilane was found to be an effective linker for the immobilization of the polyoxometalate K6CoSiW11O39 on a fused silica surface.  We are now looking at how they adsorb to a surface coated with a sulfonic acid group similar to Nafion which is currently being used in fuel cells.  We are also now using phosphotungstic acid, PW12O40, which is the most commonly used polyoxometalate in fuel cell applications.

Cade Fox - mentor: Jeff Vargason


Title: Expression and purification of a putative suppressor of RNA silencing

My first goal for the summer was to optimize the purification of p14, a protein found in the Pothos Latent Virus. The protein p14 is a silencing suppressor and is responsible for protecting the Pothos Latent Virus from the defenses of its host cells. In my first project, I used different strains of E. coli to produce p14. Temperature, expression time, and chemical concentration were varied to find the optimum conditions to produce the largest amount of p14. Once the best methods to express p14 are found, I plan to produce large amounts of the protein in order to study its molecular properties and structure.

Kirsten Hoffman - mentor:  Carlisle Chambers


Title: Phase Separation of Mixed Amide-Containing Thiols on Gold Surfaces

The purpose of this research is to study self-assembled monlayers (SAM’s) that involve a single layer of molecules that spontaneously attach (adsorb) to a solid surface.  They offer a well-defined system that can be used to develop materials with high-density two-dimensional nanoscale features.  Present research includes the synthesis of an electro-active sulfur terminated compound (thiol) that contains three amide groups and the analysis of how this compound interacts with a single amide thiol in a SAM.  Analysis of this SAM system will also provide insight on how similar thiol groups phase separate which is important in order to reproducibly and rationally generate materials with nanoscale features.

Jonathan White - mentor: Carlisle Chambers


Title: Synthesis of Amphiphillic Polyoxometalates using P2W17O6110- and V3P2W15O629- Compounds

The objective of this research is the synthesis of amphiphilic organic-inorganic hybrid systems that take advantage of the unique physical and chemical properties of polyoxometalates (POMs).  POMs have multiple accessible redox sites that are spectroscopically distinct, and can be arranged into hybrid systems by different techniques.  Once synthesized, the alkyl-substituted, amphiphilic POMs must be purified in order to form the desired amphiphillic systems.

Flora Yong - mentor: Jeff Vargason


Title: Specificity of p19 protein for DNA

RNA silencing inhibits gene expression via double-stranded RNA (dsRNA) that is processed into small interfering RNA (siRNA) which blocks the expression of complementary mRNA. This mechanism is a way in which gene expression in model organisms and cultured cells can be reduced.  Also, RNA silencing could potentially be used therapeutically to reduce gene expression or as an anti-viral treatment.  The specificity and affinity of which the viral protein p19 binds siRNAs (preventing them from functioning properly) is size-dependent (Vargason et al., 2003).  The purpose of this research is to determine the specificity and affinity of p19 for DNA in the A-conformation.  DNA in the A-conformation is of particular interest because of the similarity in structure between RNA and A-DNA.  Also, DNA with varying degrees of propensity for the A-confirmation can be produced (Vargason et al., 2001).  Taking into consideration the structural similarity between RNA and A-DNA, it is hypothesized that p19 will bind with increasing specificity for DNA with increasing degree of propensity for the A-conformation.