| This thesis is concerned primarily with the dynamical properties of proteins. The principal tool employed herein is nuclear magnetic resonance (NMR), used to measure spin relaxation in nuclei throughout the molecules of interest. In the first case, two homologous domains are compared to analyze their dynamical properties in the context of their biological function. These type III fibronectin domains from fibronectin and tenascin each bear the arginine-glycine-aspartate (RGD) tripeptide motif known to be central to cell adhesion. In the second case, a protein folding transition is analyzed---that of the GCN4 DNA-binding domain, which is substantially unfolded in the absence of its DNA ligand. In addition, NMR methods have been developed for the measurement of spin relaxation, and for the study of proteins in general. |
