Improved representation of two-dimensional NMR spectra by local rescaling

Abstract

Two-dimensional NMR spectroscopy has developed into a powerful method for the determination of the three-dimensional structure of biological macromolecules ( 1-3). The information used for the calculation of the spatial structure must be extracted from the rather complex 2D NMR spectra of macromolecules which usually consist of a very large number of resonance peaks. Although automated or computeraided evaluation of 2D NMR spectra is becoming more and more important (414)) 2D experiments are still evaluated by inspection of the contour plot, a graphical representation of the two-dimensional spectra ( 15). The information content of a contour plot depends on the plot levels chosen: too low plot levels obscure cross peaks by noise and by artifacts; too high plot levels make weak but significant cross peaks