DESCRIPTION: The New York Structural Biology Center, a 501(c) (3) corporation governed by a Board representing nine research institutions, proposes to purchase a 900 MHz NMR spectrometer for research in structural biology, and seeks fluids for art of the Cost of the spectrometer. The principal investigators and other investigators will share in the use of this resource, and will encourage other users. Research to be constructed includes structure determination of proteins and nucleic acids, dynamics studies, protein folding, and development of methods of isotopic labeling, application to higher molecular weights, and application to membrane proteins. These studies are part of programs aimed at understanding both basic scientific problems in structural biology and at physiological and pathological processes involved in many diseases of development, cancer, muscle skeletal disorders, neurological diseases, and infectious diseases. The investigators include leading structural biologists using NMR, and leading experimentalists and methods developers in the area. This rich intellectual environment will be fruitful for scientific productivity, creativity, and collaboration using the proposed instrument. The 900 MHz spectrometer will be housed in a 10,000 sq. if. extension now in construction, contiguous with the NYSBC's existing laboratory. The investigators will have access to' 800 MHz and lower field instruments, so that the 900 MHz system Can be used selectively for those experimentalists requiring ultra high field. Specific requirement S for ultra high field include applications to large molecular weight systems using transverse optimize relaxation spectroscopy (TROSY) and its ''derivatives, magnetic orientation for measurement of residual dipolar couplings, and field-dependent CSA, dynamics, and other relaxation-related phenomena.