Mass Spectrometry Strategies for Ultra-fast Mixing and Incubation

2 Mass Spectrometry Strategies for Ultra-fast Mixing and Incubation 

In one of the pioneering studies, conformational changes were induced in a model protein (bovine ubiquitin) by adding methanol to aqueous acidic solutions of the analyte [61], Using HDX in combination with ESI-MS, it was possible to follow conformational changes in bovine ubiquitin and in chicken egg lysozyme (due to the reduction of the disulfide 

In an interesting work, Liuni et al. [72] investigated pre-steady state conformational dynamics in an active enzyme using combined time-resolved ESI-MS and sub-second HDX. Here, biocatalytic processes were monitored as time-dependent intensity changes of reaction intermediates. Conformational dynamics was analyzed by the rate and magnitude of deuterium uptake [72], 

Protein folding studies generally concern liquid-phase phenomena however, HDX reactions can also be conducted in the gas phase (e.g., [84-90] for an overview see [91]). For instance, multiply charged ions of several model proteins reacted with DjO in a vacuum following pseudo-first-order kinetics [85]. It was also observed that removing solvent significantly increased conformational rigidity. In other work, ions of bovine ubiquitin were 

Borchers, C.H., Konermann, L. (2010) Characterizing Short-lived Protein Folding Intermediates by Top-down Hydrogen Exchange Mass Spectrometry. Anal. Chem. 82 8591 8597. Copyright (2010) American Chemical Society 

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