Purification of active recombinant trypanosome alternative oxidase

FEBS Lett. 2003 Mar 13;538(1-3):35-40. doi: 10.1016/s0014-5793(03)00120-0.


Trypanosome alternative oxidase (TAO) is the terminal oxidase of the respiratory chain in long slender bloodstream forms of African trypanosomes. TAO is a cytochrome-independent, cyanide-insensitive quinol oxidase. These characteristics are distinct from those of the bacterial quinol oxidases, proteins that belong to the heme-copper terminal oxidase superfamily. The inability to purify stable TAO has severely hampered biochemical studies of the alternative oxidase family. In the present study, we were able to purify recombinant TAO to homogeneity from Escherichia coli membranes using the detergent digitonin. Kinetic analysis of the purified TAO revealed that the specific inhibitor ascofuranone is a competitive inhibitor of ubiquinol oxidase activity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Electrophoresis, Polyacrylamide Gel
  • Enzyme Inhibitors / pharmacology
  • Mitochondrial Proteins
  • Oxidoreductases / antagonists & inhibitors
  • Oxidoreductases / isolation & purification*
  • Plant Proteins
  • Recombinant Proteins / antagonists & inhibitors
  • Recombinant Proteins / isolation & purification
  • Sesquiterpenes / pharmacology
  • Trypanosoma / enzymology*


  • Enzyme Inhibitors
  • Mitochondrial Proteins
  • Plant Proteins
  • Recombinant Proteins
  • Sesquiterpenes
  • Oxidoreductases
  • alternative oxidase
  • ascofuranone