Chapter 6. Kinetic Studies by Mass Spectrometry

  1. Igor A. Kaltashov and
  2. Stephen J. Eyles

Published Online: 27 JAN 2005

DOI: 10.1002/0471705179.ch6

Mass Spectrometry in Biophysics: Conformation and Dynamics of Biomolecules

Mass Spectrometry in Biophysics: Conformation and Dynamics of Biomolecules

How to Cite

Kaltashov, I. A. and Eyles, S. J. (2005) Kinetic Studies by Mass Spectrometry, in Mass Spectrometry in Biophysics: Conformation and Dynamics of Biomolecules, John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/0471705179.ch6

Author Information

  1. University of Massachusetts at Amherst, USA

Publication History

  1. Published Online: 27 JAN 2005
  2. Published Print: 6 APR 2005

Book Series:

  1. Wiley-Interscience Series in Mass Spectrometry

Book Series Editors:

  1. Dominic M. Desiderio2 and
  2. Nico M. M. Nibbering3

Series Editor Information

  1. 2

    Departments of Neurology and Biochemistry, University of Tennessee Health Science Center, USA

  2. 3

    Vrije Universiteit Amsterdam, The Netherlands

ISBN Information

Print ISBN: 9780471456025

Online ISBN: 9780471705178

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Keywords:

  • time-resolved measurements;
  • quenched-flow techniques;
  • stopped-flow techniques;
  • kinetic intermediate states;
  • enzyme kinetics

Summary

In the previous chapter we demonstrated the power of mass spectrometry for the study of biomolecules at equilibrium. For instance we can allow a sample to equilibrate in the solution conditions of choice and then acquire a spectrum at leisure. By varying the solvent composition it becomes possible to infer some of the properties of alternate conformations transiently sampled in the equilibrium population, yielding information about the structural features of the states that are visited. Analysis of charge state distributions exhibited in ESI mass spectra provides valuable information about the degree of “foldedness” of these conformational ensembles, and from hydrogen exchange experiments it is possible to measure the exposure to solvent of these species. Kinetic studies are crucial to a complete understanding of biochemical reaction mechanisms, including protein folding. Kinetic investigations enable rate constants and activation energies to be derived, and by monitoring the progress of the reaction it may be possible to observe transient intermediates that give key mechanistic information. Transient intermediates detected during protein folding can provide insight into the dominant pathway of folding; likewise short lived intermediate species during the catalytic cycle of enzyme activity gives valuable information about the reaction mechanism. However these intermediates are, by their very nature, short lived so, unlike equilibrium measurements, there is the added challenge of time scale. Once a reaction is initiated it must be rapidly transferred to an observation point in order to be followed kinetically. In this chapter we will discuss some of the methodologies developed to study these kinetic events.