Abstract
The double ring indole residue of tryptophan has been the work-horse probe of protein structure for decades because its fluorescence emission spectrum is readily acquired, and more importantly, the result is exquisitely sensitive to protein environment and structure. However, analysis of the fluorescence result has often not included the energy of the indole electronic states responsible for spectral shifts. My approach to revealing these electronic state changes is spectroscopic, combining the techniques of ultraviolet resonance Raman spectroscopy (UVRR), absorption, and steady-state fluorescence excitation and emission.
My presentation will begin with a discussion of the application of UVRR spectroscopy to tryptophan in proteins, and then explain how UVRR is being used, in conjunction with fluorescent techniques, to arrive at a more comprehensive picture of indole electronic energy shifts with changes in tryptophan environment.