Regulation of alternative oxidase kinetics by pyruvate and intermolecular disulfide bond redox status in soybean seedling mitochondria.

Journal Article (Journal Article)

Two factors known to regulate plant mitochondrial cyanide-resistant alternative oxidase activity, pyruvate and the redox status of the enzyme's intermolecular disulfide bond, were shown to differently affect activity in isolated soybean seedling mitochondria. Pyruvate stimulated alternative oxidase activity at low levels of reduced ubiquinone, shifting the threshold level of ubiquinone reduction for enzyme activity to a lower value. The disulfide bond redox status determined the maximum enzyme activity obtainable in the presence of pyruvate, with the highest rates occurring when the bond was reduced. With variations in cellular pyruvate levels and in the proportion of reduced alternative oxidase protein, a wide range of enzyme activity is possible in vivo.

Full Text

Duke Authors

Cited Authors

  • Umbach, AL; Wiskich, JT; Siedow, JN

Published Date

  • July 1994

Published In

Volume / Issue

  • 348 / 2

Start / End Page

  • 181 - 184

PubMed ID

  • 8034038

Electronic International Standard Serial Number (EISSN)

  • 1873-3468

International Standard Serial Number (ISSN)

  • 0014-5793

Digital Object Identifier (DOI)

  • 10.1016/0014-5793(94)00600-8


  • eng