Using 1HN amide temperature coefficients to define intrinsically disordered regions: An alternative NMR method

摘要

This report describes a cost‐effective experimental method for determining an intrinsically disordered protein (IDP) region in a given protein sample. In this area, the most popular (and conventional) means is using the amide (¹H^N) NMR signal chemical shift distributed in the range of 7.5–8.5 ppm. For this study, we applied an additional step: analysis of ¹H^N chemical shift temperature coefficients (¹H^N‐CSTCs) of the signals. We measured ¹H–¹⁵N two‐dimensional NMR spectra of model IDP samples and ordered samples at four temperatures (288, 293, 298, and 303 K). We derived the ¹H^N‐CSTC threshold deviation, which gives the best correlation of ordered and disordered regions among the proteins examined (below −3.6 ppb/K). By combining these criteria with the newly optimized chemical shift range (7.8–8.5 ppm), the ratios of both true positive and true negative were improved by approximately 19% (62–81%) compared with the conventional “chemical shift‐only” method.