title: [Effect of extraction and subsequent addition of manganese ions on photooxidation of chlorophyll P(680) in the photosystem II preparations].
abstract: Effect of reversible removal of Mn on the amplitude of photoinduced absorbance changes (ΔA) related to photooxidation of chlorophyll P(680) in pea oxygen -- evolving photosystem 2 (PS(2)) preparations has been studies. It is shown that after complete removal of Mn the amplitude of ΔA is increased by a factor of 7--8 and it is decreased again to the initial value upon subsequent addition of MnCl(2). This reactivation needs four Mn atoms per one reaction centre (RC) of PS(2). In the presence of 3 μM MgCI(2) the reactivation requires two Mn atoms per RC of PS2. The obtained data confirm our earlier conclusion that a four-atomic Mn centre functions in the donor side of PS(2); two of them can be replaced by either Mg(2+) or other divalent metals.
authors.forename: S I
authors.initials: SI
authors.lastname: Allakhverdiev
authors.forename: M A
authors.initials: MA
authors.lastname: Shafiev
authors.forename: V V
authors.initials: VV
authors.lastname: Klimov
mesh_terms: D002413:Cations, Divalent; D002712:Chlorides / Q000494:pharmacology; D002734:Chlorophyll / Q000378:metabolism*; D002736:Chloroplasts / Q000378:metabolism*; D008345:Manganese / Q000378:metabolism*; D017895:Manganese Compounds / Q000494:pharmacology; D010084:Oxidation-Reduction; D055668:Photochemical Processes; D045332:Photosystem II Protein Complex / Q000378:metabolism*
chemical_list: D002413:Cations, Divalent; D002712:Chlorides; D017895:Manganese Compounds; D045332:Photosystem II Protein Complex; D002734:Chlorophyll; D008345:Manganese; C025167:P-680; C025340:manganese chloride