Davidson College Department of Chemistry
Official Davidson College Chemistry Department Page
Student Research
Gabriel Perlow (‘14), Biochemistry. Dr. Jeffrey Myers and Dr. Mark Barsoum.
Conformational changes of Parkinson’s Disease-related protein α-synuclein upon exposure to hormone mimetics.
Various projects are active in the Myers lab. In mine, we produce α-synuclein inside of E. coli cells and then harvest the cells and purify the protein. With the pure samples, we use spectroscopic (light interaction) methods to determine its 3-dimensional shape, also known as a “conformation”. Individual units of α-synuclein (monomers) are intrinsically disordered, adopting many different, extended conformations in rapid succession. In Parkinson’s Disease the conformation of α-synuclein stabilizes in a certain way, causing monomers to aggregate into long, orderly rods called amyloid fibrils. These fibrils may be toxic to neurons. α-Synuclein has been shown to form these fibrils under a variety of conditions, some of which involve exposure to pesticides. A particular pesticide, Paraquat, bears structural resemblance to ubiquitous industrial chemicals that have been shown to mimic hormones that our bodies produce. We are exposing α-synuclein to those hormone mimetic compounds, and gauging the extent of fibrillation.
Our current goals are to replicate studies showing fibrillation of α-synuclein when exposed to Paraquat, as well as measure relative rates of fibrillation between Paraquat, the hormone mimetics, and controls.
In the future, students may begin testing molecules that are similar to those we are currently studying to investigate changes in fibrillation rates due to small structural differences.
Jessica Annonio (‘14) Chemistry. Dr. Cindy Hauser.
Effect of water pipe height on particulate formation in mainstream waterpipe smoke
Hookah (also known as narghile, shisha, and hubble-bubble) is a form of tobacco use created in the 15th century India and has since spread to various Middle East and Mediterranean regions and most recently Western countries, including the United States. The tobacco is frequently flavored with a sweet tasting paste called ma’assel, placed in the head and heated; a vacuum pump pulls air through the tobacco, body, filtration media, and the hose. Pulling air over the heating source (either charcoal or ceramic heat) melts and vaporizes semivolatile compounds. These compounds in mainstream smoke, filtration media, or tobacco, can then be characterized quantitatively and qualitatively looking at chemical composition of the particulate matter, particle size distribution, and mass concentration. Previous work in the Hauser lab has characterized the mainstream smoke of waterpipes using a variety of smoking parameters such as puff duration, puff interval, filtration media and its quantity, and herbal shisha. My current independent research project involves characterizing the effect of water pipe height on particulate formation in mainstream waterpipe smoke based on mass concentration and particle size distribution.
Robert Hagerty (’15), Chemistry. Dr. Cindy Hauser.
Snyder Research Group
From left to right: Eric Medici, Matt Brady, Rachel Barkley, Renato Guerrieri , Dr. Nicole Snyder, Karl Wold, George Mukosera.
Eric Medici (’15), Chemistry. Dr. Nicole Snyder.
Synthesis of Rhamnose donors containing 2-O-sulfonyl protecting groups for the synthesis of β-rhamnosidic linkages.
β-Rhamnosidic linkages are found in a number of important glycan structures on the surface of bacterial cell membranes. For example, β-rhamnosides are a primary component of several cell surface antigens of invasive Streptococcus bacterium such as Pneumococcal Serotype 31 (PS31) and Group B Streptococcus (GBS). These sugars are often highly antigenic and as such are important targets for vaccine development. However, one limitation in the development of glycan structures containing β-rhamnosidic linkages is the lack of reliable sugar donors that consistently yield high β-selectivity under standard glycosylation conditions.
In our ongoing efforts to design protecting groups with the ability to generate β-rhamnosidic linkages, we endeavor to synthesize rhamnose donors with 2-O-sulfonly protecting groups such as the Npes and Fson donors in. In addition to providing a similar β-directing effect to Crich’s 2-O-sulfonyl protecting group, the Npes and Fson groups can be removed under mild conditions.
This semester we plan to complete the synthesis of four glucose acceptors. We then plan to study the ability of the 2-O-sulfonyl donor to form β-rhamnosidic linkages using a series of standard glycosylation reactions with those four glucose acceptors along with four additional receptors we already have. We have also provided RhamBB donor to Karl Wold (’15) who will use this building block to continue to explore the scope and limitations of the glycosylations reactions for the synthesis of PS31.
Davidson SAACS 