Inactivation of the Na+-translocating NADH:ubiquinone oxidoreductase from Vibrio alginolyticus by reactive oxygen species

Eur J Biochem. 2002 Feb;269(4):1287-92. doi: 10.1046/j.1432-1033.2002.02770.x.

Abstract

The Na+-translocating NADH:quinone oxidoreductase (Na+-NQR) from Vibrio alginolyticus was inactivated by reactive oxygen species. Highest Na+-NQR activity was observed in anaerobically prepared membranes that exhibited 1:1 coupling of NADH oxidation and Q reduction activities (1.6 U x mg(-1)). Optical and EPR spectroscopy documented the presence of b-type cytochromes, a [2Fe-2S] cluster and an organic radical signal in anaerobically prepared membranes from V. alginolyticus. It is shown that the [2Fe-2S] cluster previously assigned to the Na+-NQR originates from the succinate dehydrogenase or the related enzyme fumarate reductase.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins*
  • Iron-Sulfur Proteins / analysis
  • Oxidation-Reduction
  • Quinone Reductases / antagonists & inhibitors*
  • Reactive Oxygen Species / pharmacology*
  • Succinate Dehydrogenase / analysis
  • Uncoupling Agents / pharmacology
  • Vibrio / enzymology*

Substances

  • Bacterial Proteins
  • Iron-Sulfur Proteins
  • Reactive Oxygen Species
  • Uncoupling Agents
  • Succinate Dehydrogenase
  • sodium-translocating NADH-quinone reductase
  • Quinone Reductases