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Two separate transhydrogenase activities are present in plant mitochondria

Bykova, Natalia V.; Rasmusson, Allan G. LU ; Igamberdiev, Abir U.; Gardeström, Per and Møller, Ian M (1999) In Biochemical and Biophysical Research Communications 265(1). p.106-111
Abstract

Inside-out submitochondrial particles from both potato tubers and pea leaves catalyze the transfer of hydride equivalents from NADPH to NAD+ as monitored with a substrate-regenerating system. The NAD+ analogue acetylpyridine adenine dinucleotide is also reduced by NADPH and incomplete inhibition by the complex I inhibitor diphenyleneiodonium (DPI) indicates that two enzymes are involved in this reaction. Gel-filtration chromatography of solubilized mitochondrial membrane complexes confirms that the DPI-sensitive TH activity is due to NADH-ubiquinone oxidoreductase (EC 1.6.5.3, complex I), whereas the DPI-insensitive activity is due to a separate enzyme eluting around 220 kDa. The DPI-insensitive TH activity is... (More)

Inside-out submitochondrial particles from both potato tubers and pea leaves catalyze the transfer of hydride equivalents from NADPH to NAD+ as monitored with a substrate-regenerating system. The NAD+ analogue acetylpyridine adenine dinucleotide is also reduced by NADPH and incomplete inhibition by the complex I inhibitor diphenyleneiodonium (DPI) indicates that two enzymes are involved in this reaction. Gel-filtration chromatography of solubilized mitochondrial membrane complexes confirms that the DPI-sensitive TH activity is due to NADH-ubiquinone oxidoreductase (EC 1.6.5.3, complex I), whereas the DPI-insensitive activity is due to a separate enzyme eluting around 220 kDa. The DPI-insensitive TH activity is specific for the 4B proton on NADH, whereas there is no indication of a 4A-specific activity characteristic of a mammalian-type energy-linked TH. The DPI-insensitive TH may be similar to the soluble type of transhydrogenase found in, e.g., Pseudomonas. The presence of non-energy-linked TH activities directly coupling the matrix NAD(H) and NADP(H) pools will have important consequences for the regulation of NADP-linked processes in plant mitochondria.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Biochemical and Biophysical Research Communications
volume
265
issue
1
pages
6 pages
publisher
Academic Press
external identifiers
  • Scopus:0033547417
ISSN
0006-291X
DOI
10.1006/bbrc.1999.1627
language
English
LU publication?
yes
id
69158017-5469-490a-b833-010362164297
date added to LUP
2016-05-31 21:23:34
date last changed
2016-08-10 13:58:14
@misc{69158017-5469-490a-b833-010362164297,
  abstract     = {<p>Inside-out submitochondrial particles from both potato tubers and pea leaves catalyze the transfer of hydride equivalents from NADPH to NAD<sup>+</sup> as monitored with a substrate-regenerating system. The NAD<sup>+</sup> analogue acetylpyridine adenine dinucleotide is also reduced by NADPH and incomplete inhibition by the complex I inhibitor diphenyleneiodonium (DPI) indicates that two enzymes are involved in this reaction. Gel-filtration chromatography of solubilized mitochondrial membrane complexes confirms that the DPI-sensitive TH activity is due to NADH-ubiquinone oxidoreductase (EC 1.6.5.3, complex I), whereas the DPI-insensitive activity is due to a separate enzyme eluting around 220 kDa. The DPI-insensitive TH activity is specific for the 4B proton on NADH, whereas there is no indication of a 4A-specific activity characteristic of a mammalian-type energy-linked TH. The DPI-insensitive TH may be similar to the soluble type of transhydrogenase found in, e.g., Pseudomonas. The presence of non-energy-linked TH activities directly coupling the matrix NAD(H) and NADP(H) pools will have important consequences for the regulation of NADP-linked processes in plant mitochondria.</p>},
  author       = {Bykova, Natalia V. and Rasmusson, Allan G. and Igamberdiev, Abir U. and Gardeström, Per and Møller, Ian M},
  issn         = {0006-291X},
  language     = {eng},
  month        = {11},
  number       = {1},
  pages        = {106--111},
  publisher    = {ARRAY(0xa106cd0)},
  series       = {Biochemical and Biophysical Research Communications},
  title        = {Two separate transhydrogenase activities are present in plant mitochondria},
  url          = {http://dx.doi.org/10.1006/bbrc.1999.1627},
  volume       = {265},
  year         = {1999},
}