Festival of Science - Student Abstracts | St. Lawrence University Biochemistry

Festival of Science - Student Abstracts

Festival of Science 2018 was held Friday, April 27, 2018.

Anne Buck - Chemistry, Faculty Advisors: Samuel Tartakoff
Progress Towards Efficient Synthesis of Morphine Analogues Using the Wagner-Jauregg Reaction

A Diels-Alder cycloaddition allows for the creation of two new sigma bonds along with a new six membered ring. This reaction occurs as a result of the pi bonds found in the diene and dienophile being higher in energy and therefore less stable, interacting to produce more stable sigma bonds. The Diels Alder reaction allows for different conformations to be produced depending on how the diene interact with the dienophile resulting in new steriocenters. The Wagner-Jauregg reaction, is a specialized Diels Alder reaction in which the diene is an aromatic ring. Aromatic compounds are exceptionally sable and unreactive due to an extended conjugated network. It normally requires very harsh conditions to cause an aromatic ring to react, which is the main challenge of the Wagner-Jauregg. This method can be used in the production of opioid- like compounds. Opioid molecules are composed of 5 rings, with the proper one ring starting material, through a Wagner-Jauregg reaction it is possible to create a three-ring structure in one step. Two starting compounds were produced through Wittig reactions followed by purification via column chromatography and characterization via proton nuclear magnetic resonance. These compounds then underwent a series of variable reaction conditions, such as high temperatures, to try and promote a Wagner-Jauregg intermolecular cycloaddition with maleic anhydride. Up to the present date, we have produced a compound with highly electron withdrawing functional groups, which we are trying to currently characterize.

Funding: University Fellowship, Stradling Scholarship Fund

Jack Mechler - Biochemistry, Faculty Advisors: Nadia Marano and Lorraine Olendzenski
Isolating and Characterizing Functional Amyloid Fibers from Microbacterium sp.

Functional bacterial amyloids make up an important structural component of biofilms, and little is known about their variance in structure throughout nature. This research aimed to adjust isolation procedures developed by Heather Raimer (2017) for an archaeon, to obtain amyloid fibers from Microbacterium sp. that was isolated from the soil of a pig farm by Abby Korn (2014), and shown to test positive for amyloids using the Thioflavin T (ThT) assay by Hunter Berrus (2015) and Jordan Koloski (2016). ThT assays during different bacterial growth conditions showed that the Microbacterium produce more amyloids closely associated with the cells when grown on agar plates, as opposed to liquid media. Early protein isolation trials showed that amyloids more closely associated with the cells were better candidates for isolation. Therefore, plate-grown amyloids were separated from the cells using sonication, and purified from other components using differential centrifugation and polyacrylamide gel electrophoresis. To further purify this amyloidogenic material, and to characterize the monomers that it is composed of, it was depolymerized in formic acid, further purified with differential centrifugation, dried in a speedvac, and resuspended in both water and formic acid with 1M urea. The sample in formic acid and urea was run on an SDS-page gel to determine the size of its monomers and the extent of the purification, and the sample in water examined under a scanning electron microscope, according to previously derived methods. Isolating and imaging these novel functional amyloids will be another step in our understanding of bacterial amyloids.

Funding: University Fellowship

Natasha Turyasingura - Chemistry, Faculty Advisor: Emily Dixon
A Study of Gene Regulation in Yeast under Stress:  The Mechanism of Binding of Rpd3 to the Promoter Region of NDP genes in Saccharomyces cerevisiae

When Saccharomyces cerevisiae yeast cells are subjected to stressful conditions, the cells respond by altering certain cellular processes to adapt and survive. One such stressful condition is nutrient deprivation. The TOR pathway has been found to be a central regulator of both cell size and proliferation. Rapamycin is a small molecule that binds to and inhibits the TOR protein eliciting a transcriptional response that is reminiscent of nutrient deprivation. This transcriptional response results in the activation and repression of specific groups of genes. The repression of select genes has been studied to occur by the action of the histone deacetylase Rpd3. Rpd3 binds to the promoters of rapamycin-repressible genes via the transcriptional repressors Dot6/Tod6 to the GATGAG sequence in the promoter region. Here, we investigate whether Rpd3 binds to the promoters of NDP genes to activate them in the same way that it binds to the promoters of genes repressed by Rpd3. To do this, we approach the question in two ways: we delete the GATGAG sequence in the promoter of the GAP1 gene to determine if Rpd3 still binds to the GAP1 promoter; and we tag Rpd3 in a Dot6/Tod6 mutant to determine whether the presence of Dot6/Tod6 is necessary for the binding of Rpd3 to the promoter of GAP1 (and other NDP genes).

Funding: Biology Department