This proposal requests support to obtain a Time-Resolved Spectrofluorometer. This equipment enables one to measure very fast processes, occurring in the time scales of microsecond to 100 picoseconds, in biological energy conversion and light- induced structural changes in biomolecules and membranes. The proposed instrument will be the only one of its kind at the University of Nebraska. Since this instrument is essential in studying very fast reactions involved in biological energy conversion (as in photosynthesis and photobiology) and structural changes of the biomolecules systems (as biomembranes and proteins), a number of researchers at UNL are expected to make use of this equipment in their research. Graduate students will also be exposed to this equipment for their training and graduate research. The initial experiments anticipated to be performed with this equipment include studies of (1) the phototransformation of phytochrome, a light-regulator of gene expression for the biogenesis of photosynthetic apparatus in green plants, (2) the structure and topography of photosynthetic pigments, and (3) structure-function relationships and dynamic properties of DNA, proteins and model biological membranes. The first two areas of the proposed studies focus on elucidating the primary molecular processes of the tetrapyrrole-based photoreceptors in plant photobiological systems.
