An unusual isotope effect on substrate inhibition in the oxidation of arachidonic acid by lipoxygenase

J Am Chem Soc. 2003 Jul 30;125(30):8988-9. doi: 10.1021/ja035977t.

Abstract

Soybean lipoxygenase catalyzes the oxidation of arachidonic acid to 15S-HPETE. The reaction displays strong substrate inhibition with unlabeled substrate but no discernible substrate inhibition with arachidonic acid labeled with deuterium at C13, the site of hydrogen/deuterium atom abstraction. The unusual behavior is due primarily to a large kinetic isotope effect on Km,O2 as a result of the strong selection against deuterium in the abstraction step.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Arachidonic Acid / antagonists & inhibitors
  • Arachidonic Acid / chemistry
  • Arachidonic Acid / metabolism*
  • Deuterium
  • Glycine max / enzymology
  • Glycine max / metabolism
  • Hydroxyeicosatetraenoic Acids / metabolism
  • Kinetics
  • Linoleic Acid / chemistry
  • Linoleic Acid / metabolism
  • Lipoxygenase / chemistry
  • Lipoxygenase / metabolism*
  • Lipoxygenase Inhibitors / chemistry
  • Lipoxygenase Inhibitors / metabolism
  • Oxidation-Reduction

Substances

  • Hydroxyeicosatetraenoic Acids
  • Lipoxygenase Inhibitors
  • Arachidonic Acid
  • 15-hydroxy-5,8,11,13-eicosatetraenoic acid
  • Linoleic Acid
  • Deuterium
  • lipoxygenase L-1
  • Lipoxygenase