This NSF Young Investigator grant from the Organic Dynamics Program supports the work of Professor Thomas C. Pochapsky at Brandeis University. The structure and dynamics of self-assembling systems will be determined using NMR and chromatographic techniques. Two-dimensional NMR techniques will be used to determine the structures of putidaredoxin and closely related analogues prepared by site-directed mutagenesis. Other biological macromolecules that will be investigated include a chimeric protein created by replacing a four-residue tight turn in interleukin-1-beta with the ten-residue trypsin binding loop from alpha-1-antitrypsin. Ion pair structure will be investigated by measuring inter-ion pair NOE's. %%% The three dimensional structure of proteins will be determined by using a spectroscopic tool which gives a response which can be related to the distance between pairs of atomic nuclei. Distance data for several pairs of nuclei greatly restrict the possible solution geometry of the protein and in many cases provide a unique structure. This work will provide important information necessary to understand the forces which control molecular self-assembly.