Finding intermediates in the O2 activation pathways of non-heme iron oxygenases

Acc Chem Res. 2007 Jul;40(7):475-83. doi: 10.1021/ar700052v. Epub 2007 Jun 14.

Abstract

Intermediates in the reaction cycle of an oxygenase are usually very informative with respect to the chemical mechanism of O 2 activation and insertion. However, detection of these intermediates is often complicated by their short lifetime and the regulatory mechanism of the enzyme designed to ensure specificity. Here, the methods used to detect the intermediates in an extradiol dioxygenase, a Rieske cis-dihydrodiol dioxygenase, and soluble methane monooxygenase are discussed. The methods include the use of alternative, chromophoric substrates, mutagenesis of active site catalytic residues, forced changes in substrate binding order, control of reaction rates using regulatory proteins, and initialization of catalysis in crystallo.

Publication types

  • Research Support, N.I.H., Extramural
  • Review

MeSH terms

  • Animals
  • Binding Sites
  • Catalysis
  • Crystallography, X-Ray
  • Dioxygenases / chemistry*
  • Dioxygenases / metabolism
  • Humans
  • Kinetics
  • Nonheme Iron Proteins / chemistry*
  • Nonheme Iron Proteins / metabolism
  • Oxidation-Reduction
  • Oxygen / chemistry
  • Oxygen / metabolism*
  • Oxygenases / chemistry*
  • Oxygenases / metabolism
  • Reactive Oxygen Species / chemistry
  • Reactive Oxygen Species / metabolism

Substances

  • Nonheme Iron Proteins
  • Reactive Oxygen Species
  • Oxygenases
  • Dioxygenases
  • methane monooxygenase
  • extradiol dioxygenase
  • Oxygen