Three-dimensional electrophoretic NMR correlation spectroscopy

A novel method of three-dimensional electrophoretic NMR correlation spectro scopy (3D EP-COSY) has been proposed, developed, and implemented. It has a demonstrated potential of facilitating simultaneous structural assignments of multiple proteins in mixtures. The principle is to add a pulsed DC elect ric field that introduces a new dimension of electrophoretic flow, in which resonances of different molecules can be separated by their electrophoreti c migration rates without physical separation. As a result, two COSY spectr a were simultaneously obtained in a single 3D EP-COSY experiment from a mix ture of 150 mM L-aspartic acid and 148 mM 4,9-dioxa-,1,12-dodecanediamine w ith concurrent resolution of their chemical shifts and J-coupling constants . This approach creates a new horizon of multidimensional electrophoretic N MR, The technical advance opens doors for structure characterization of com plex protein systems and protein interactions, which are at the basis of bi ochemical mechanisms and the phenomena of living systems. (C) 2000 Academic Press.