Hydrogen-deuterium exchange study of an allosteric energy cycle.

Elucidation of mechanisms of energy transduction through macromolecules in allosteric systems requires application of a broad range of techniques and approaches. High-resolution structures of the end states in an allosteric system provide invaluable clues about allosteric mechanism. Thermodynamic and kinetic studies reveal the rules that govern the transitions between states in the system. Acquisition of detailed molecular level information about allosteric mechanism requires interrogation of the structural and dynamic properties of both intermediates and end states in the allosteric cycle. Many experimental and computational tools have been developed to probe allostery. Among these are hydrogen-deuterium exchange detected by either NMR spectroscopy or mass spectrometry. This article provides a detailed description of application of hydrogen exchange detected by mass spectrometry (HDX-MS) to investigate an allosteric system.