Standard Article

Kinetic Isotope Effects in Enzymes

Biomolecules Analysis

  1. Amnon Kohen,
  2. Daniel Roston,
  3. Vanja Stojković,
  4. Zhen Wang

Published Online: 15 DEC 2010

DOI: 10.1002/9780470027318.a9161

Encyclopedia of Analytical Chemistry

Encyclopedia of Analytical Chemistry

How to Cite

Kohen, A., Roston, D., Stojković, V. and Wang, Z. 2010. Kinetic Isotope Effects in Enzymes. Encyclopedia of Analytical Chemistry. .

Author Information

  1. The University of Iowa, Department of Chemistry, Iowa City, IA, USA

Publication History

  1. Published Online: 15 DEC 2010


Kinetic isotope effects (KIEs) have progressed to become one of the most useful analytical techniques to study enzymatic reactions and can answer a variety of questions ranging from the basic mechanism of a reaction to the structure of a transition state (TS) and the role of quantum mechanical tunneling. Here, we briefly discuss the development of the theory behind KIEs with an emphasis on how it guides the interpretation of experimental data. We then present some of the instrumentation and techniques commonly used for KIE experiments, followed by a number of different examples from the enzymology literature wherein KIEs have been used to probe chemical transformations, with an emphasis on the effects of quantum mechanical tunneling on KIEs.


  • enzymes;
  • kinetics;
  • isotope effects;
  • tunneling;
  • dihydrofolate reductase;
  • alcohol dehydrogenase;
  • thymidylate synthase