Chloride‐depletion of photosynthetic water oxidase
- 27 December 1993
- journal article
- Published by Wiley in FEBS Letters
- Vol. 336 (2) , 304-308
- https://doi.org/10.1016/0014-5793(93)80825-f
Abstract
Chloride depletion blocks the normal four-step progress of photosynthetic water oxidation. We studied proton release in chloride-depleted thylakoids which were dark-adapted and excited by flashing light. Proton release was blocked from the second flash on, possibly leaving an uncompensated positive charge in the catalytic centre. The reduction of P+680 by Tyrz was still very rapid (⪡ 10 μs). From the third flash on, P+680 was reduced more slowly (70 μs200 μs), and by an electrogenic back-reaction. The uncompensated positive charge may be the reason why the rapid reduction of P+680 by Tyrz is prevented and the transmembrane charge-pair recombination is facilitatedKeywords
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