Anno2016
AutoriSantabarbara S, Zucchelli G
AbstractThe oxidation kinetics of phyllo(semi) quinone (PhQ), which acts as an electron transfer (ET) intermediate in the Photosystem I reaction centre, are described by a minimum of two exponential phases, characterised by lifetimes in the 10-30 ns and 150-300 ns ranges. The fastest phase is considered to be dominated by the oxidation of the PhQ molecule coordinated by the PsaB reaction centre subunit (PhQ(B)), and the slowest phase is dominated by the oxidation of the PsaA coordinated PhQ (PhQ(A)). Testing different energetic schemes within a unified theory-based kinetic modelling approach provides reliable limit-values for some of the physical-chemical parameters controlling these ET reactions: (i) the value of Delta G(0) associated with PhQ(A) oxidation is smaller than similar to+30 meV; (ii) the value of the total reorganisation energy (lambda(t)) likely exceeds 0.7 eV; (iii) different mean nuclear modes are coupled to PhQ(B) and PhQ(A) oxidation, the former being larger, and both being >= 100 cm(-1)
RivistaPccp. Physical Chemistry Chemical Physics (print)
ISSN1463-9076
Impact factor
Volume18
Pagina inizio9687
Pagina fine9701
Autori IBFGiuseppe ZUCCHELLI, Stefano SANTABARBARA
Linee di Ricerca IBFMD.P01.005.001
Sedi IBFIBF.MI