Improving the chemical shift dispersion of multidimensional NMR spectra of intrinsically disordered proteins

Intrinsically disordered proteins (IDPs) have recently attracted the attention of the scientific community challenging the well accepted structure–function paradigm. In the characterization of the dynamic features of proteins nuclear magnetic resonance spectroscopy (NMR) is a strategic tool of investigation. However the peculiar properties of IDPs, with the lack of a unique 3D structure and their high flexibility, have a strong impact on NMR observables (low chemical shift dispersion, efficient solvent exchange broadening) and thus on the quality of NMR spectra. Key aspects to be considered in the design of new NMR experiments optimized for the study of IDPs are discussed. A new experiment, based on direct detection of 13Cα, is proposed.This work has been supported in part by the Joint Research Activity and Access to Research Infrastructures (Bio–NMR, contract 261863) and by the Marie Curie ITN programs (IDPbyNMR, contract 264257) in the EC 7th Framework. S·S. acknowledges financial support for a short stay fellowship associated to Project CTQ2008–0080 from the Spanish Ministerio de Economía y Competitividad