Faculty Profiles

« Return to Faculty List

Antony R. Crofts Professor of Biochemistry and Biophysics Ph.D. 1965, University of Cambridge, UK Molecular mechanisms in photosynthetic energy conversion Antony R. Crofts 149 Davenport Hall, MC-147 607 S. Mathews Urbana, IL 61801 217-333-2043 a-crofts@life.uiuc.edu

The main research interest of the lab is in structure/function relationships in the energy transducing electron transfer complexes of respiration and photosynthesis. We use several complementary approaches. The general idea is to study the mechanism using spectroscopic approaches appropriate to the rapid reactions involved, and relate that to the known structure. Since we are able to modify the proteins we are interested in by site-directed mutagenesis, we can see how specific changes in structure modify the function, and relate these to molecular mechanism. The main systems we are working on at present are the bc1 complex (Complex III of the respiratory chain) and photosystem II. We study the bc1 complex in the photosynthetic bacterium Rhodobacter sphaeroides, where we can activate it by a flash of light, and then watch the electrons skip along the photosynthetic chain to assay the function. Our structural studies are in collaboration with Dr. Ed Berry at UC Berkeley, who has solved structures of the mitochondrial bc1-complex. The crystallographic structures are static, and in order to get more dynamic structural information, we are also using spectroscopic techniques which can probe structural and functional parameters for individual residues and redox centers. These methods include high-resolution EPR approaches (ESEEM and ENDOR), and FTIR spectroscopy. We study photosystem II in the alga Chlamydomonas reinhardtii, in which context we can readily perform specific mutagenesis, and use similar approaches to study functional aspects. This area promises to expand rapidly in the near future as structural information at atomic resolution becomes available. A third area of current interest is in the application of biophysical methods to studies of photosynthesis in intact plants. We have developed novel video imaging instruments that use fluorescence to measure changes in photosynthetic physiology, and are applying these in a collaborative study of insect damage to crops and forests.