The broad objective of this research is to elucidate membrane protein structure and dynamics using advanced solid-state NMR spectroscopy. Membrane proteins regulate cellular transport and cell signaling, thus they are essential for cell survival. Knowledge of their three-dimensional structures is crucial for understanding their functions. Solid-state NMR is a promising method for studying the molecular structure of membrane proteins in their native environment of lipid bilayers. In this CAREER project, the structure and dynamics of a 22 kDa membrane-bound protein, colicin Ia channel domain, will be investigated using NMR techniques suitable for extensively isotopically labeled proteins. a-helical and b-sheet segments in colicin will be identified and specific structural constraints will be measured using chemical shift anisotropies, correlated dipolar couplings, and 1H-1H internuclear distances. The depth of insertion of the protein into the lipid bilayer will be determined by 1H spin diffusion techniques. The dynamics of the colicin backbone and sidechain will be characterized using anisotropic couplings, lineshapes, and relaxation time constants. These studies should provide insight into the mechanism of conformational changes of colicin Ia and other proteins that refold to accomplish their functions. Related to these research objectives are educational initiatives to modernize the undergraduate chemistry curriculum. A protein structure module for general chemistry will be designed to integrate research with teaching, and create web pages for undergraduate physical chemistry courses. The participation of women in chemistry will be encouraged by recruiting women summer interns into the laboratory.
