Oxygen rebound mechanism

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In biochemistry, the oxygen rebound mechanism is the pathway for hydroxylation of organic compounds by iron-containing oxygenases. Many enzymes affect the hydroxylation of hydrocarbons as a means for biosynthesis, detoxification, gene regulation, and other functions. These enzymes all utilize Fe-O centers that convert C-H bonds into C-OH groups. The oxygen rebound mechanism mechanism starts with abstraction of H from the hydrocarbon, giving an organic radical and an iron hydroxide. In the rebound step, the organic radical attacks the Fe-OH center to give an alcohol group, which is initially bound to Fe as a ligand, but dissociates, allowing the cycle to start anew. This mechanistic scenario is an alternative to the direct insertion of an O center into a C-H bond. The pathway is an example of C-H activation.[1]

Steps in an oxygen rebound mechanism: H-atom abstraction, oxygen rebound, alcohol decomplexation.

Three main classes of these enzymes are cytochrome P450, alpha-ketoglutarate-dependent hydroxylases, and nonheme-diiron hydroxylases.

References[edit]

  1. ^ Huang, X.; Groves, J. T. (2017). "Beyond ferryl-mediated hydroxylation: 40 years of the rebound mechanism and C–H activation". JBIC Journal of Biological Inorganic Chemistry. 22: 185–207. doi:10.1007/s00775-016-1414-3. PMC 5350257.CS1 maint: uses authors parameter (link)