Formate bound to cytochrome oxidase can be removed by cyanide and by reduction

Biochim Biophys Acta. 1996 Dec 18;1277(3):237-42. doi: 10.1016/s0005-2728(96)00105-3.

Abstract

Using 14C-radiolabeled formate we have found that the rapid form of oxidized cytochrome oxidase can bind up to 1 mol of formate. Treatment of this formate-ligated enzyme with excess cyanide releases 97% of the radiolabel while reduction of formate-labeled enzyme with NADH+ruthenium releases 80-85% of the radioactivity. These data are most simply interpreted by assuming that formate binds to the heme iron of cytochrome a3.

Publication types

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

MeSH terms

  • Animals
  • Carbon Radioisotopes
  • Cattle
  • Cyanides / pharmacology*
  • Electron Transport Complex IV / metabolism*
  • Formates / metabolism*
  • Kinetics
  • NAD / metabolism
  • Oxidation-Reduction
  • Ruthenium / metabolism

Substances

  • Carbon Radioisotopes
  • Cyanides
  • Formates
  • NAD
  • formic acid
  • Ruthenium
  • Electron Transport Complex IV