New facts about CdCl2 action on the photosynthetic apparatus of spinach chloroplasts and Its comparison with HgCl2 action

Title:

New facts about CdCl2 action on the photosynthetic apparatus of spinach chloroplasts and Its comparison with HgCl2 action

Creator:

Šeršeň, F. and Kráľová, K.

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:8c95ba11-ba9e-4c08-b787-2b130a6cbbe1
uuid:8c95ba11-ba9e-4c08-b787-2b130a6cbbe1
issn:0300-3604
doi:10.1023/A:1015612330650

Subject:

cadmium, EPR spectroscopy, mercury, photosynthetic electron transport, and Spincia oleracea

Type:

model:article and TEXT

Format:

bez média and svazek

Description:

Using EPR spectroscopy it was found that CdCl2 and HgCl2 interact (1) with the intermediates Z./D., i.e. with the tyrosine radicals on the donor side of photosystem (PS) 2 situated in the 161st position in D1 and D2 proteins; (2) with the primary donor of PS1 (P700) whereby the oxidation of chlorophyll (Chl) a dimer in the reaction centre of PS1 occurs yet in the dark; (3) with the manganese cluster which is situated in the oxygen evolving complex. Due to these interactions of investigated metal chlorides with the photosynthetic apparatus, the interruption of the photosynthetic electron transport through photosynthetic centres occurs. Monitoring of time dependence of EPR signal I of chloroplasts treated with CdCl2 or HgCl2 after switching off the light suggests that all mechanisms, i.e. direct, cyclic, and non-cyclic reductions of P700+ are damaged. The formation of complexes between mercury or cadmium ions and amino acid residues constituting photosynthetic peptides was suggested as possible mechanism of their inhibitory action. The higher HgCl2 efficiency in comparison with that of CdCl2 was explained by higher ability of mercury ions to form complexes with amino acids, what was demonstrated by their apparent binding constants: K = 10 200 M-1 for Hg2+ ions, and K = 3 700 M-1 for Cd2+ ions. and F. Šršeň, K. Kráľová.

Language:

Multiple languages

Rights:

http://creativecommons.org/licenses/by-nc-sa/4.0/
policy:public

Coverage:

575-580

Source:

Photosynthetica | 2001 Volume:39 | Number:4

Harvested from:

CDK

Metadata only:

false