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Tags
HERO ID
1337298
Reference Type
Journal Article
Title
Reversible inhibition of Co(2) fixation by ribulose 1,5-bisphosphate carboxylase/oxygenase through the synergic effect of arsenite and a monothiol
Author(s)
Sudhani, HPK; García-Murria, M-J; Moreno, J
Year
2013
Is Peer Reviewed?
1
Journal
Plant, Cell and Environment
ISSN:
0140-7791
EISSN:
1365-3040
Volume
36
Issue
6
Page Numbers
1160-1170
Language
English
PMID
23216059
DOI
10.1111/pce.12050
Web of Science Id
WOS:000318176800008
Abstract
The activity of the photosynthetic carbon-fixing enzyme, ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco), is partially inhibited by arsenite in the millimolar concentration range. However, micromolar arsenite can fully inhibit Rubisco in the presence of a potentiating monothiol such as cysteine, cysteamine, 2-mercaptoethanol or N-acetylcysteine, but not glutathione. Arsenite reacts specifically with the vicinal Cys172-Cys192 from the large subunit of Rubisco and with the monothiol to establish a ternary complex which is suggested to be a trithioarsenical. The stability of the complex is strongly dependent on the nature of the monothiol. Enzyme activity is fully recovered through the disassembly of the complex after eliminating arsenite and/or the thiol from the medium. The synergic combination of arsenite and a monothiol acts also in vivo stopping carbon dioxide fixation in illuminated cultures of Chlamydomonas reinhardtii. Again, this effect may be reverted by washing the cells. However, in vivo inhibition does not result from the blocking of Rubisco since mutant strains carrying Rubiscos with Cys172 and/or Cys192 substitutions (which are insensitive to arsenite in vitro) are also arrested. This suggests the existence of a specific sensor controlling carbon fixation that is even more sensitive than Rubisco to the arsenite-thiol synergism.
Keywords
Chlamydomonas reinhardtii; carbon fixation; enzyme inhibition; photosynthesis; Rubisco
Tags
IRIS
•
Arsenic Hazard ID
1. Initial Lit Search
PubMed
PubMed
WOS
Considered New
PubMed
Considered New
2. Lit Search Updates through Oct 2015
PubMed
WOS
Considered
4. Considered through Oct 2015
6. Cluster Filter through Oct 2015
7. Other Studies through Oct 2015
Other
iAs MOA Literature Categorization
Cytotoxicity and Regenerative Proliferation
Epigenetic Mechanisms
Oxidative Stress
•
Arsenic (Inorganic)
1. Literature
PubMed
Lit search updates through Oct 2015
3. Hazard ID Screening
Other potentially supporting studies
4. Adverse Outcome Pathways/Networks Screening
Excluded/Not relevant
Title/Abstract screening
•
Arsenic MOA
1. MOA Literature Screening
MOA Cluster
3. Excluded
Other not relevant
Dragon Screened
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