Measurement of backbone hydrogen-deuterium exchange in the type III secretion system needle protein PrgI by solid-state NMR

In this report we present site-specific measurements of amide hydrogen-deuterium exchange rates in a protein in the solid state phase by MAS NMR. Employing perdeuteration, proton detection and a high external magnetic field we could adopt the highly efficient Relax-EXSY protocol previously developed for liquid state NMR. According to this method, we measured the contribution of hydrogen exchange on apparent N-15 longitudinal relaxation rates in samples with differing D2O buffer content. Differences in the apparent T-1 times allowed us to derive exchange rates for multiple residues in the type III secretion system needle protein. (C) 2017 The Authors. Published by Elsevier Inc.