We have constructed (and continue to develop) a laser-based facility for time-resolved fluorescence spectroscopy of biomolecules. This facility provides rapid collection and analysis of luminescence data related to macromolecular size, flexibility, folding and structural fluctuations. Our time-correlated laser fluorometer was used to study the folding and dynamics of several proteins. We focused most of our effort on DNA- binding proteins that control the transcription of DNA blueprints into the """"""""field copies"""""""" (m-rna) used to build proteins in cells. Fluorescence was used to measure distances between proteins and the sections of DNA they control, to look at the wobbling of proteins in the complex, and to reveal internal changes in the bound protein. We completed our studies of oct-pou, a transcription factor that recognizes two """"""""classes"""""""" of sites. It was seen to """"""""read"""""""" DNA by changing shape. We continued collaborative studies on HIV integrase, the enzyme responsible for incorporation of the AIDS virus into host cells; on Heat Shock Factor domains, to help ascertain its' binding mechanism; and on TFIIIA - internal control region (5s RNA gene) interactions. We began work this year on specially labeled GAL4(5HT) versions of the (herpes) activator VP-16 to test the flexibility in complexes with promoter elements like TBP. We also studied the self-associative properties of globin activator USF and interleukin 8. This year we also continued efforts to adapt our laser instruments to the imaging of tissues. In particular, we patented two electronic laser scanning devices that use discoloration to find BB-sized objects almost an inch inside tissue. We also developed a more precise (30 micron) imager that can provide slices of skin images up to 1/8"""""""" deep, then scan sideways.
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