Conformational studies of the robust 2-Cys peroxiredoxin Salmonella typhimurium AhpC by solution phase hydrogen/deuterium (H/D) exchange monitored by electrospray ionization mass spectrometry

▶ First HX-MS studies of the robust peroxiredoxin, StAhpC, and two mutants in which the Thr-77 was substituted by isoleucine, a decamer-disruptive mutation, or valine, a decamer-promoting mutation. ▶ Global HX-MS studies indicate that disulfide reduction causes a reduction in overall conformational stability. ▶ HX-MS at the peptide level demonstrate enhanced conformational mobility in the peroxidatic active site of loop as a consequence of disulfide formation. ▶ HX-MS studies reveal allosteric interaction between the mutations in the dimer-dimer interface and the active site loop.