Fluorescence Spectroscopy of Macromolecules

Submitted by Patricia B. O'Hara

Research Interests: An atom or molecule in its lowest energy state (the ground state) can be made to absorb energy and move into a short lived excited state. When that atom or molecule returns to the ground state, energy can be released as light. This phenomenon, known as fluorescence, can be observed, and properties such as lifetimes, energies, and wavelength distributions of the emitted light can be measured. These properties carry information about the environment, structure, and dynamics of the system containing the excited atom or molecule. In the O'Hara lab, experiments are conducted to reveal some of the inner workings of these systems both in large assemblies of molecules (bulk phases) and one molecule at a time (single molecule).  Using fluorescence, our lab studies alpha crystallin, the protein that prevents protein aggregation and cataract formation in the eye, and the binding of pesticides and environmental toxins to the estrogen receptor.  In addition, we have in the past examined affinity maturation in antibodies, the folding of synthetic polymers, signal transduction in calmodulin, and protein­DNA flexibility in t7 RNA polymerase.  We have built and are using a single molecule spectrometer to gain even more information in these systems as we can look at individual molecules instead of measuring system averages.

Our lab is also interested in the ways certain foods can act as nutraceuticals: that is small metabolites in the food help to preserve health and delay disease.  In particular, we are exploring antioxidants and their role in preventing diseases such as cancer, cardiovascular disease, and arthritis. Our favorite source of polyphenols is olive oil.