title: Interaction of various types of photosystem I complexes with exogenous electron acceptors.
abstract: Interaction of photosystem I (PS I) complexes from cyanobacteria Synechocystis sp. PCC 6803 containing various quinones in the A1-site (phylloquinone PhQ in the wild-type strain (WT), and plastoquinone PQ or 2,3-dichloronaphthoquinone Cl2NQ in the menB deletion strain) and different numbers of Fe4S4clusters (intact WT and FX-core complexes depleted of FA/FBcenters) with external acceptors has been studied. The efficiency of interaction was estimated by measuring the light-induced absorption changes at 820 nm due to the reduction of the special pair of chlorophylls (P700+) by an external acceptor(s). It was shown that externally added Cl2NQ is able to effectively accept electrons from the terminal iron-sulfur clusters of PS I. Moreover, the efficiency of Cl2NQ as external acceptor was higher than the efficiency of the commonly used artificial electron acceptor, methylviologen (MV) for both the intact WT PS I and for the FX-core complexes. The comparison of the efficiency of MV interaction with different types of PS I complexes revealed gradual decrease in the following order: intact WT > menB > FX-core. The effect of MV on the recombination kinetics in menB complexes of PS I with Cl2NQ in the A1-site differed significantly from all other PS I samples. The obtained effects are considered in terms of kinetic efficiency of electron acceptors in relation to thermodynamic and structural characteristics of PS I complexes.
authors.affiliation: A.N. Belozersky Institute of Physical-Chemical Biology, Moscow State University, Moscow, Russia.
authors.forename: Anastasia A
authors.initials: AA
authors.lastname: Petrova
authors.affiliation: Department of Bioengineering and Bioinformatics, Moscow State University, Moscow, Russia.
authors.forename: Baina K
authors.initials: BK
authors.lastname: Boskhomdzhieva
authors.affiliation: A.N. Belozersky Institute of Physical-Chemical Biology, Moscow State University, Moscow, Russia.
authors.forename: Georgy E
authors.initials: GE
authors.lastname: Milanovsky
authors.affiliation: A.N. Belozersky Institute of Physical-Chemical Biology, Moscow State University, Moscow, Russia.
authors.forename: Olga A
authors.initials: OA
authors.lastname: Koksharova
authors.affiliation: A.N. Belozersky Institute of Physical-Chemical Biology, Moscow State University, Moscow, Russia.
authors.forename: Mahir D
authors.initials: MD
authors.lastname: Mamedov
authors.affiliation: A.N. Belozersky Institute of Physical-Chemical Biology, Moscow State University, Moscow, Russia.|A.N. Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, Moscow, Russia.
authors.forename: Dmitry A
authors.initials: DA
authors.lastname: Cherepanov
authors.affiliation: A.N. Belozersky Institute of Physical-Chemical Biology, Moscow State University, Moscow, Russia. semenov@genebee.msu.ru.
authors.forename: Alexey Yu
authors.identifier: http://orcid.org/0000-0003-1035-0381
authors.initials: AY
authors.lastname: Semenov
mesh_terms: D004583:Electrons; D007700:Kinetics; D045331:Photosystem I Protein Complex / Q000378:metabolism*; D046939:Synechocystis / Q000378:metabolism*
chemical_list: D045331:Photosystem I Protein Complex
keywords: 2,3-dichloro-1,4-naphthoquinone; Electron transfer; External electron acceptor; Methylviologen; Midpoint redox potentials; Photosystem I