caa a22 4500 445889756 CHVBK 20180317145612.0 cr unu---uuuuu 170323e20110301xx s 000 0 eng 10.1007/s11120-011-9637-1 doi (NATIONALLICENCE)springer-10.1007/s11120-011-9637-1 Effect of crowding on the electron transfer process from plastocyanin and cytochrome c6 to photosystem I: a comparative study from cyanobacteria to green algae [Elektronische Daten] [Manuel Hervás, José Navarro] Plastocyanin and cytochrome c 6, the alternate donor proteins to photosystem I, can be acidic, neutral or basic; the role of electrostatics in their interaction with photosystem I vary accordingly for cyanobacteria, algae and plants. The effect of different crowding agents on the kinetics of the reaction between plastocyanin or cytochrome c 6 and photosystem I from three different cyanobacteria, Synechocystis PCC 6803, Nostoc PCC 7119 and Arthrospira maxima, and a green alga, Monoraphidium braunii, has been investigated by laser flash photolysis, in order to elucidate how molecular crowding affects the interaction between the two donor proteins and photosystem I. The negative effect of viscosity on the interaction of the two donors with photosystem I for the three cyanobacterial systems is very similar, as studied by increasing sucrose concentration. Bovine serum albumin seems to alter the different systems in a specific way, probably by means of electrostatic interactions with the donor proteins. Ficoll and dextran behave in a parallel manner, favouring the interaction by an average factor of 2, although this effect is somewhat less pronounced in Nostoc. With regards to the eukaryotic system, a strong negative effect of viscosity is able to overcome the favourable effect of any crowding agent, maybe due to stronger donor/photosystem I electrostatic interactions or the structural nature of the eukaryotic photosystem I-enriched membrane particles. Springer Science+Business Media B.V., 2011 Arthrospira nationallicence Cytochrome c6 nationallicence Crowding nationallicence Laser flash photolysis nationallicence Monoraphidium nationallicence Nostoc nationallicence Photosystem I nationallicence Plastocyanin nationallicence Synechocystis nationallicence BSA : Bovine serum albumin nationallicence Cyt c 6 : Cytochrome c6 nationallicence k 2 : Second-order rate constant nationallicence k 2 0 : Second-order rate constant in the absence of any added viscogen nationallicence k 2/ k 20 : Relative second-order rate constant in the presence of viscogens nationallicence k obs : Observed pseudo first-order rate constant nationallicence Pc : Plastocyanin nationallicence PSI : Photosystem I nationallicence Hervás Manuel Instituto de Bioquímica Vegetal y Fotosíntesis, Centro de Investigaciones Científicas Isla de la Cartuja, Universidad de Sevilla & CSIC, Américo Vespucio 49, 41092, Sevilla, Spain aut Navarro José Instituto de Bioquímica Vegetal y Fotosíntesis, Centro de Investigaciones Científicas Isla de la Cartuja, Universidad de Sevilla & CSIC, Américo Vespucio 49, 41092, Sevilla, Spain aut Photosynthesis Research Springer Netherlands 107/3(2011-03-01), 279-286 0166-8595 107:3<279 2011 107 11120 https://doi.org/10.1007/s11120-011-9637-1 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11120-011-9637-1 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Hervás Manuel Instituto de Bioquímica Vegetal y Fotosíntesis, Centro de Investigaciones Científicas Isla de la Cartuja, Universidad de Sevilla & CSIC, Américo Vespucio 49, 41092, Sevilla, Spain aut NATIONALLICENCE 700 1- Navarro José Instituto de Bioquímica Vegetal y Fotosíntesis, Centro de Investigaciones Científicas Isla de la Cartuja, Universidad de Sevilla & CSIC, Américo Vespucio 49, 41092, Sevilla, Spain aut NATIONALLICENCE 773 0- Photosynthesis Research Springer Netherlands 107/3(2011-03-01), 279-286 0166-8595 107:3<279 2011 107 11120 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer