title: Enthalpy/entropy driven activation of the first interquinone electron transfer in bacterial photosynthetic reaction centers embedded in vesicles of physiologically important phospholipids.
abstract: The thermodynamics and kinetics of light-induced electron transfer in bacterial photosynthetic RCs are sensitive to physiologically important lipids (phosphatidylcholine, cardiolipin and phosphatidylglycerol) in the environment. The analysis of the temperature-dependence of the rate of the P(+)Q(A)(-)Q(B)-->P(+)Q(A)Q(B)(-) interquinone electron transfer revealed high enthalpy change of activation in zwitterionic or neutral micelles and vesicles and low enthalpy change of activation in vesicles constituted of negatively charged phospholipids. The entropy change of activation was compensated by the changes of enthalpy, thus the free energy change of activation ( approximately 500 meV) did not show large variation in vesicles of different lipids.
authors.affiliation: CNR, Istituto per i Processi Chimico-Fisici, Sezione di Bari, c/o Dipartimento di Chimica, Via Orabona, 4 I-70124 Bari, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Milano
authors.forename: Márta
authors.initials: M
authors.lastname: Dorogi
authors.forename: Kornélia
authors.initials: K
authors.lastname: Szebényi
authors.forename: László
authors.initials: L
authors.lastname: Nagy
authors.forename: Péter
authors.initials: P
authors.lastname: Maróti
authors.forename: György
authors.initials: G
authors.lastname: Váró
authors.forename: Livia
authors.initials: L
authors.lastname: Giotta
authors.forename: Angela
authors.initials: A
authors.lastname: Agostiano
authors.forename: Massimo
authors.initials: M
authors.lastname: Trotta
mesh_terms: D016227:Benzoquinones / Q000737:chemistry*; D002308:Cardiolipins / Q000737:chemistry* / Q000378:metabolism; D004579:Electron Transport; D019277:Entropy; D010713:Phosphatidylcholines / Q000737:chemistry* / Q000378:metabolism; D010715:Phosphatidylglycerols / Q000737:chemistry* / Q000378:metabolism; D045322:Photosynthetic Reaction Center Complex Proteins / Q000737:chemistry* / Q000378:metabolism; D012242:Rhodobacter sphaeroides / Q000737:chemistry / Q000378:metabolism
chemical_list: D016227:Benzoquinones; D002308:Cardiolipins; D010713:Phosphatidylcholines; D010715:Phosphatidylglycerols; D045322:Photosynthetic Reaction Center Complex Proteins; C004532:quinone