This proposal requests partial support for the purchase of a 500 MHz nuclear magnetic resonance spectrometer and a data analysis/graphics workstation for research on protein structure and function by investigators at the University of North Carolina. The work station would allow us to process and plot data obtained remotely. This would facilitate our use of the other NMR facilities in the Triangle area. Dr. Gary Pielak will use 2-D NMR to investigate the effects of mutation on the 3-dimensional structure and function of cytochrome c. Dr. Thomas N. Sorrell will examine the influence of altered iron ligands on the same protein. Dr. Richard Wolfenden will use high-field NMR to characterize complexes of enzymes with transition-state and multisubstrate analog inhibitors, as a guide to improvements in drug design. Dr. Mary Ellen Jones will investigate the effects of active site modification on the catalytic function of fragments of mouse orotate decarboxylase, expressed in E. coli. Dr. Bruce Erickson will perform 2-D NMR studies on synthetic polypeptides designed to adopt specific structures in solution and provide a scaffolding for the introduction of functional groups, to obtain new binding agents and catalysts. Dr. Susan Lord will use mutagenesis to explore the role of fibrinogen's primary structure in determining its secondary and tertiary structure, and its interactions with thrombin, as an aid to understanding blood coagulation. Dr. Richard G. Hiskey will use the instrument to elucidate the structure of gamma-carboxyglutamic acid domain peptides in prothrombin. Dr. Howard Reisner will examine the effects of mutations on the three-dimensional structure of the EGF-like domain of Factor IX and other blood coagulation proteins. Dr. Richard Tidwell will investigate the configurations of novel synthetic protease inhibitors. Dr. Avram Gold will use the instrument to examine mechanisms by which porphyrins activate polycyclic enviromnental hydrocarbons, as models for the physiological reactions that generate the ultimate carcinogens.