This award provides funds for the further development of the use of Nuclear Magnetic resonance (NMR) for studies of the 3 dimensional structure of proteins and nucleic acids in solution. The approach developed by Gorenstein and his colleagues, the hybrid matrix/complete relaxation matrix program (or MORASS), has proven highly productive. Planned work should increase the accuracy and ease of application of these techniques. Determination of the three dimensional structure of biopolymers such as proteins and nucleic acids, and its relationship to the biological function of the polymers, is a central problem in modern biology. The most successful approach to the study of large molecules like proteins has come with the use of crystallographic methods. These methods, however, are limited to study of the highly ordered structures found in crystals; the results may or may not be directly applicable to the structure of (active) molecules in solution. Many investigators now see the use of NMR as the most promising approach to studies of the solution structure of a variety of biomolecules. However, further refinement of experimental techniques and the analytical tools needed for interpretation of the spectroscopic data is crucial to progress in the application of this powerful tool.