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Reversible inhibition of photochemistry of photosystem II by Ca 2+ removal from intact cells of Anacystis nidulans
Author(s) -
Brand Jerry J.,
Mohanty Prasanna,
Fork David C.
Publication year - 1983
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(83)80222-1
Subject(s) - photosystem ii , photochemistry , chemistry , fluorescence , dcmu , photosystem , photosynthesis , biophysics , yield (engineering) , photosynthetic reaction centre , photosystem i , cyanobacteria , quantum yield , biochemistry , biology , electron transfer , materials science , physics , bacteria , optics , genetics , metallurgy
Depletion of Ca 2+ from Anacystis nidulans produces an inhibition of O 2 evolution that is accompanied both at 39°C and 77 K by a loss of chlorophyll fluorescence of variable yield. This indicates that Ca 2+ ‐depletion causes disruption of normal photosystem II function, manifested by the disappearance of photoreduction of Q. Delayed light emission in the ms time range is also eliminated in Ca 2+ ‐depleted cells, which confirms that Ca 2+ removal prevents charge separation and recombination in reaction centers of photosystem II. Readdition of Ca 2+ to depleted cells restores fully the fluorescence of variable yield and delayed light emission, as well as O 2 evolution. Thus, Ca 2+ may be a required component for photosystem II in A. nidulans .