Blog
About

7
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: not found

      Ferredoxin:NADP+ oxidoreductase as a target of Cd2+ inhibitory action--biochemical studies.

      Phytochemistry

      chemistry, pharmacology, Catalysis, Cysteine, drug effects, metabolism, Cytochromes c, Electron Transport, Ferredoxin-NADP Reductase, antagonists & inhibitors, enzymology, Ferredoxins, Molecular Structure, Oxidation-Reduction, Photosynthesis, Plant Leaves, Spinacia oleracea, Cadmium

      Read this article at

      ScienceOpenPublisherPubMed
      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          The ferredoxin:NADP+ oxidoreductase (FNR) catalyses the ferredoxin-dependent reduction of NADP+ to NADPH in linear photosynthetic electron transport. The enzyme also transfers electrons from reduced ferredoxin (Fd) or NADPH to the cytochrome b(6)f complex in cyclic electron transport. In vitro, the enzyme catalyses the NADPH-dependent reduction of various substrates, including ferredoxin, the analogue of its redox centre - ferricyanide, and the analogue of quinones, which is dibromothymoquinone. This paper presents results on the cadmium-induced inhibition of FNR. The K(i) value calculated for research condition was 1.72 mM. FNR molecule can bind a large number of cadmium ions, as shown by the application of cadmium-selective electrode, but just one ion remains bound after dialysis. The effect of cadmium binding is significant disturbance in the electron transfer process from flavin adenine dinucleotide (FAD) to dibromothymoqinone, but less interference with the reduction of ferricyanide. However, it caused a strong inhibition of Fd reduction, indicating that Cd-induced changes in the FNR structure disrupt Fd binding. Additionally, the protonation of the thiol groups is shown to be of great importance in the inhibition process. A mechanism for cadmium-caused inhibition is proposed and discussed with respect to the in vitro and in vivo situation. Copyright © 2010 Elsevier Ltd. All rights reserved.

          Related collections

          Author and article information

          Journal
          21071046
          10.1016/j.phytochem.2010.10.010

          Comments

          Comment on this article