FRONTIERS IN 2D NMR OF PARAMAGNETIC METALLOPROTEINS

The possibilities and the limitations of 2D NMR for the structural characterization of paramagnetic metalloproteins are reviewed. We survey the general strategies for 2D H-1 NMR investigations of hyperfine shifted signals. Careful adaptation of classical 2D NMR experiments to fast relaxing systems results in the detection of previously not observed scalar and dipolar connectivities, thus leading to the specific assignment of selected resonances. The approach is of general applicability for paramagnetic metalloproteins. We report here on the application of the application of the method to an iron sulfur protein and a heme protein. In both cases specific assignment of several hyperfine shifted signals, corresponding to active site protons, were obtained; this allowed significant insight into the structure-function relationships of these metalloproteins.