Role of deprotonation events in ubihydroquinone:cytochrome c oxidoreductase from bovine heart and yeast mitochondria.

@article{Brandt1997RoleOD,
  title={Role of deprotonation events in ubihydroquinone:cytochrome c oxidoreductase from bovine heart and yeast mitochondria.},
  author={Ulrich Brandt and Juergen Guenther Okun},
  journal={Biochemistry},
  year={1997},
  volume={36 37},
  pages={11234-40}
}
The pH dependence of bovine and yeast cytochrome bc1 complex catalyzing electron transfer from ubi- and plastohydroquinone to cytochrome c have been analyzed. The pH dependence of the steady-state rate was found to be governed by two protonable groups, one of which (pK approximately 6.6) has to be deprotonated while the other (pK approximately 9.2) has to be protonated to allow catalysis. Using ubideuteroquinone instead of ubihydroquinone as a substrate resulted in 1.4- and 1.7-fold lower… CONTINUE READING