Evaluation of the use of silicomolybdate as an electron acceptor for photosystem 2 in photoinhibition research

Title:

Evaluation of the use of silicomolybdate as an electron acceptor for photosystem 2 in photoinhibition research

Creator:

Schansker, G. and van Rensen, J. J. S.

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:2293e561-cd27-4f7d-9fed-297422415e06
uuid:2293e561-cd27-4f7d-9fed-297422415e06
urnnbn:urn:nbn:cz:aba007-000fat

Type:

model:internalpart and TEXT

Format:

print

Description:

Silicomolybdate (SiMo) is an electron acceptor that has many characteristics, the ignorance of which makes an interpretation of the results quite troublesome. In photoinhibitíon experiments the photosystem 2 (PS 2) actívity can be best monitored if 1 pM dibromotíiymoquinone (DBMIB) is added after photoinhibitory treatment and SiMo is added in the light. Diuron (DCMU) may complicate interpretation of the results as it is also a competítíve inhibitor of SiMo binding at pH 7.6. The binding niche of SiMo is probably located at the stroma side between the fourth and fifth helix of the Dl and D2 proteins close to Q^- The whole chain actívity was much more affected by the photoinhibitory treatment than the PS 2 actívity itself Uncoupling of electron flow by addition of ammonium chloride accelerated the rate of photoinhibitíon. Photoinhibitory treatment decreased not only the Hill actívity at photon saturation, but also decreased the quantum yield and increased the photon flux density yielding half maximum rate of electron flow (K^). Decrease of quantum yield indicated that the photochemistry of PS 2 was afiected; increase of indicated a coiďormational change of the SiMo binding site. In experiments on PS 2 actívity monitored witíi SiMo, DCMU had no protectíve effect on the damage of the electron transport chain between water and QA.

Language:

Multiple languages

Rights:

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

Coverage:

145-157 and 163-175

Source:

Photosynthetica | 1992 Volume:27 | Number:1-2

Harvested from:

CDK

Metadata only:

false