Peptide–Column Interactions and Their Influence on Back Exchange Rates in Hydrogen/Deuterium Exchange-MS

• DOI: 10.1007/s13361-013-0639-4
• Publication Date: 2013-05-06T16:01:54Z
• Authors: Joey G. Sheff; Martial Rey; David C. Schriemer
• Keywords: Hydrogen–deuterium exchange; Random coil; Residue (chemistry)

Hydrogen/deuterium exchange (HDX) methods generate useful information on protein structure and dynamics, ideally at the individual residue level. Most MS-based HDX involve a rapid proteolytic digestion followed by LC/MS analysis, with kinetics monitored peptide Localizing specific sites of is usually restricted to resolution size host because gas-phase processes can scramble deuterium throughout peptide. Subtractive may improve resolution, where levels overlapping nested peptides are used in subtractive manner localize smaller segments. In this study, we explore underlying assumption method, namely, that measured back given independent its Using series deuterated peptides, show secondary be partially retained under quenched conditions, interactions between reversed-phase LC columns both accelerate decelerate HDX, depending upon sequence length. Secondary induced through column solution-phase propensity for structure, which has effect slowing rates relative predicted random coil values. Conversely, orient random-coil conformers degree correlates charge solution, reversed using stronger ion pairing reagents. The dependency these effects length suggest improving structural HDX-MS will not offer straightforward solution increasing site resolution.