Disordered proteins hydrogen exchange kinetics

The last assumption that is required for the time correction process to be reliable is that the reaction is approximately first order with an effective rate constant that is a linear function of the chemical exchange rate constant. As discussed in Section 17.3.1, the assumption of first-order kinetics with an approximately EX2-like mechanism for disordered proteins may not be accurate. The reliability of the time correction method is only as good as the extent to which the hydrogen exchange kinetics follow an EX2-like mechanism. Taking all of these factors into account, it is clear that the use of low pH labeling to reach msec HX must be approached with some measure of caution. 

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