Two separate transhydrogenase activities are present in plant mitochondria
(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.
(Less)
- author
- Bykova, Natalia V. ; Rasmusson, Allan G. LU ; Igamberdiev, Abir U. ; Gardeström, Per and Møller, Ian M
- organization
- publishing date
- 1999-11-11
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Biochemical and Biophysical Research Communications
- volume
- 265
- issue
- 1
- pages
- 6 pages
- publisher
- Elsevier
- external identifiers
-
- pmid:10548498
- 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
- 2024-02-18 22:23:09
@article{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 = {{Elsevier}},
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}},
doi = {{10.1006/bbrc.1999.1627}},
volume = {{265}},
year = {{1999}},
}