International Collaboration in Chemistry: Mechanism of operation of the BLUF domain: blue light sensitive biosensors

Suny At Stony Brook, Stony Brook NY

Investigators

Abstract

The Analytical and Surface Chemistry Program at NSF Division of Chemistry will support the international collaborative research project of Prof. Peter Tonge of State University of New York at Stony Brook and Prof. Stephen Meech of the University of East Anglia. Profs. Tonge and Meech and their students will focus on AppA, a photoreceptor from the photosynthetic bacterium Rhodobacter sphaeroides which uses a Blue Light Using Flavin adenine dinucleotide (BLUF) domain to respond to light. Their hypothesis is that the primary event in the photoactivation of AppA is an alteration in the electronic structure of the flavin isoalloxazine ring in the excited state, which causes a rearrangement in hydrogen bonding interactions between protein and chromophore on the picosecond time scale. Ultrafast time resolved fluorescence (UTRF) will be used to reveal excited state dynamics, while femtosecond to millisecond time resolved vibrational spectroscopy (TRIR) will be used to observe the influence of photoexcitation on the host matrix structure. Data interpretation will utilize isotopic substitution and polarization measurements, coupled with the incorporation of unnatural amino acids. The resulting detailed structure- dynamics relationship will yield the first complete insight into the microscopic mechanism of photoreceptor operation. The study could lead to the development of a new generation of protein-based biosensors. The study will provide excellent training opportunities to US and UK students who will gain invaluable international research experience through extended research stays in the collaborators' laboratories. This international collaborative research project is supported jointly by NSF and the Engineering and Physical Sciences Research Council (EPSRC) in the United Kingdom. The study is also supported by the Office of International Science and Engineering (OISE) at NSF.