Spectra Using Back Calculated and Experimental Spectra

t d i e s n i f t m s u A new tool, for the simulation of N or C edited 3D-NOESY– SQC spectra using the complete relaxation matrix approach, has een developed and integrated in the program AURELIA. This ool should be particularly useful for the fast and reliable comuter assisted assignment of 3D-NOESY–HSQC spectra by comaring back-calculated and experimental spectra in an iterative rocess. Folded spectra are sometimes used to enhance the digital esolution in the indirect dimensions of multidimensional spectra. owever, these spectra are usually difficult to analyze. To simplify his assignment process we have incorporated the simulation and utomated annotation of folded peaks into the program. It is ereby possible to simulate multiple folding in all three dimensions f 3D Nor C-NOESY–HSQC spectra. By comparing experiental 3D-NOESY–HSQC spectra with spectra back calculated rom a single trial structure or a set of trial structures, a user can asily check if the final structures explain all experimental NOEs. he new feature has been successfully tested with the histidineontaining phosphocarrier protein HPr from Staphylococcus arnosus. © 1999 Academic Press