Fig. 2.

Global Back and Exposure Dependent Back Exchange Effects. A, HDX-MS data is affected by two forms of back exchange effects. This peptide should be fully exchanging in the state indicated by the blue line, yet at the longest exposure the uptake is only at ∼65% of the maximum uptake. This deficiency is the global back exchange observed. The greater back exchange at higher exposures is the result of systematic error introduced by the LEAP sample handling robot. B, After applying both the back exchange correction and the correction for systematic error introduced by the LEAP robot, the plot on the corrected plot is obtained.