Laser Probes of the Spectroscopy and Dynamics of Flexible Biomolecules and Complexes

Purdue University, West Lafayette IN

Investigators

Abstract

The Experimental Physical Chemistry program supports Timothy S. Zwier of Purdue University and his students in their studies of the single-conformation spectroscopy and conformational dynamics of small biomolecules, peptide mimics, and other small, flexible molecules and complexes cooled in supersonic expansions. These molecules have significant conformational complexity, bridging the gap between systems amenable to gas phase spectroscopy and large biomolecules. The experiments exploit direct infrared absorption or indirect stimulated emission pumping (SEP) to promote selected conformers or isomers to higher energy states. These species then are re-cooled to achieve the sharp spectra necessary for their unambiguous identification and characterization. The research expands the SEP-population transfer techniques into the mid-infrared, allowing the study of a wider range of flexible systems. This work is having a broader impact on problems of protein folding and may provide information about the laser control of molecular shape, with possible applications for using light to store information in single molecules. Graduate and undergraduate students at Purdue University, as well as faculty and students from primarily undergraduate institutions, are participating in the research.