This is a proposal to purchase an image plate detector for x-ray crystallography of proteins. Image plate detectors are a new technology poised to revolutionize protein crystallography as electronic detectors did in the 1980s. They combine the best features of both electronic detectors and photographic film. They have superior signal to noise ration at low count rates, which is essential for protein crystals. They have linear response over a wide dynamic range. Most importantly, they have superior spatial resolution compared to electronic detectors and can be manufactured in large format. Experimentally, these advantages allow the image plate to be placed close to the crystal so that a large angle is subtended and many more reflections are recorded simultaneously. The proteins being studied are molecules that function biologically as enzymes, DNA repair enzymes, antibodies, antigen complexes, proteins, determinants of pathogens, photoactive receptors, electron transfer center, oxygen binding proteins, growth factor receptors and receptor complexes, and folate cofactor enzymes involved in purine biosynthesis.
