UnidecNMR: Automatic peak detection for NMR spectra in 1-4 dimensions

Abstract To extract information from NMR experiments, users need to identify the number of resonances in the spectrum,together with characteristic features such as chemical shiftsand intensities. In many applications, particularly those involving biomolecules, this procedure is typicallya manual and laborious process. While manyalgorithms are available to tackle this problem, theirperformance tends to be inferior to that of an experienced user.Here,weintroduce UnidecNMR, which identifies resonances in NMR spectra using deconvolution. We demonstrate itsfavourable performance on 1 and 2D simulatedspectra,strongly overlapped 1D spectra of oligosaccharides and2D HSQC,3D HNCO, 3DHNCA and 3/4D methyl-methyl NOE experimental spectra from a range of proteins. UnidecNMR outperforms a number of freely available algorithms and provides results that are either of similar quality to those generated manually, or in the case of NOE data, superior. We demonstrate that introducing additionalrestraints, such as a 2D peak listwhen analysing 3 and 4D data and incorporating reflection symmetryin NOE analysisfurther improves the results. UnidecNMR outputs a back-calculated spectrum and a peak list, both of which can be easily examined using the supplied GUI. The software allows interactive processing of raw data using nmrPipe. UnidecNMR is free for academic use and can function as either part of an automatic pipeline or provide an excellent ‘first guess’ of peak locations as part of a semi-automatic analysis.