MRI: Acquisition of a circular dichroism spectropolarimeter for research and training of undergraduates at Gettysburg College

Gettysburg College, Gettysburg PA

Investigators

Abstract

This award is supported by the Major Research Instrumentation (MRI) and the Chemistry Research Instrumentation (CRIF) programs. Professor Shelli Frey from Gettysburg College and colleagues Kurt Andresen, Katherine Buettner and Lucas Thompson have acquired a circular dichroism (CD) spectrometer. Many chemical and biological molecules are chiral (having structures that are not superimposable - like our hands). Chiral molecules that are prevalent in living organisms can exist in two forms. These forms can be described as having left-handed or right-handed conformations. A CD spectrometer can determine which form or whether a mixture of both forms is present. The spectrometer can follow changes as the chiral molecule binds to another molecule (ligand), rearranges its structure, or reacts (perhaps with a drug or an antibody). Therefore, CD spectroscopy is suitable for probing protein (or other macromolecular) structures or changes to structures due to environmental conditions. CD spectroscopy has been widely used for three types of measurements: identifying the structure of proteins, studying the geometry changes during folding and unfolding of proteins, and determining the energies involved in binding interactions and protein unfolding. This spectrometer is used by undergraduates. While being trained to use this important tool, the research experience prepares the students for future careers and advanced degrees in medical and scientific fields. The instrument is also used by the NSF funded STEM Scholars program, which fosters a sense of community for students of diverse backgrounds with an interest in science fields. The acquisition of this spectropolarimeter opens new paths of research for students and faculty, and it helps students see more of the interconnected nature of science through the interdisciplinary projects. Students have access to this instrumentation in their courses, ultimately resulting in researchers prepared to enter graduate school or careers in the sciences. This award of a circular dichroism spectrometer is aimed at enhancing research and education at all levels, especially in areas such as:(a) developing titanium and vanadium binding sites in small proteins to determine secondary structure and study DNA cleavage, (b) assembling gold nanorods with electrostatically adsorbed poly-polyl-lysine to understand how molecular structure can translate into control over chiral nanoparticle assemblies, and (c) studying the folding of the nucleosome to give insight into how DNA in the nucleosome can interact with other biological molecules in vivo.