Practice question

Techniques monitoring conformational dynamics must sense time-dependent structural changes: NMR chemical exchange and relaxation, circular dichroism thermal unfolding, fluorescence resonance energy transfer distance fluctuations, and single-molecule imaging. Mass spectrometry measures mass-to-charge ratio, providing stoichiometry, post-translational modifications, and sequencing via fragmentation, but conventional measurements occur in gas phase after ionization, losing real-time solution dynamics unless combined with hydrogen-deuterium exchange pulse labeling or ion mobility. Thus among options, mass spectrometry alone does not directly report continuous conformational dynamics in native aqueous environment relevant to enzyme catalysis and allostery.