RESUMO
With the advent of structural genomics, the need for fast structural information about unknown proteins has increased. We describe a new methodology, based on 13C, 15N and ¹H chemical shift dispersion to predict the amount of secondary structure of unassigned proteins from their 15N- and/or 13C-edited heteronuclear single quantum coherence (HSQC) spectra. This methodology has been coded into a software called PASSNMR (Prediction of the Amount of Secondary Structure by Nuclear Magnetic Resonance), which can be accessed directly from the Internet. PASSNMR program is a powerful tool for screening proteins for proteomic or structural genomic investigations when used with recent methodologies that take advantage of the use of the antibiotic rifampicin to selectively label the heterologous proteins expressed in E. coli. PASSNMR analysis can be useful as a first approach to predict the amount of secondary structure in proteins to structural genomics. Information about the secondary structure of proteins can be obtained even before protein purification, with small quantities of protein, just by performing two simple nuclear magnetic resonance (NMR) experiments and using PASSNMR program.