Recommended Amount of Grant: $223,245
Summary for NSF Grant CHE-1152070: “Deciphering light induced double bond isomerization in proteins with multiconfigurational quantum chemistry”

With this award, the Chemistry of Life Processes program is supporting the research of
Dr. Massimo Olivucci of the Bowling Green State University, OH. With the help of Dr. Zhaohui Xu, a microbiologist working in the same institution (Biology Department), Olivucci intends to study the mechanism of double-bond photoisomerization in protein mutants by combining quantum chemistry and genetic techniques. The research focuses on a photochromic sensory rhodopsin from the cyanobacterium Anabaena (ASR) as a reference lab model. The investigators will construct, starting from known crystallographic data, computer models of the ASR wild-type and of a series of its mutants and study the changes in their photoisomerization dynamics via excited state trajectory computations. A sub-set of these mutants will be constructed in the laboratory for validation purposes. It is expected that the analysis of the information derived by the study of multiple series of mutants, will unveil how specific amino acid replacements can tune/control the photoisomerization.

The project has an highly international flavor. The laboratory of Prof. Hideki Kandori, Nagoya (Japan), Stefan Haacke, Strasbourg (France) and Luis Manuel Frutos, Alcala (Spain) will contribute to the research. Also the laboratory of Delmar Larsen, Unversity of California at Davis will contribute.

The Broader Impact of this project emerges from the possibility to take full control of the photochemical properties of rhodopsins. The researchers aim to establish an in silico approach for the search of functionally tuned rhodopsins that may then be engineered and employed in optogenetics and modern microscopy or used in evolutionary studies. The project stimulates collaboration across distant disciplines: computational quantum chemistry and molecular biology. Accordingly, the graduate students will receive a multidisciplinary training. The results will be disseminated not only through the conventional media but also through the on-line publication of a Protein Model Database. The results will also help to improve the quality of undergraduate/graduate courses at BGSU and thought via long-distance learning technologies. Olivucci supports the undergraduate BGSU program Building Ohio's Sustainable Energy Future by teaching how to use computers and computational chemistry tools to characterize the absorption spectra of organic compounds.