Photosystem II of green plants: on the possible role of retarded protonic relaxation in water oxidation
Autor(en): | Mulkidjanian, AY | Stichwörter: | Biochemistry & Molecular Biology; Biophysics; DIFFERENCE SPECTRA; ELECTRON-TRANSFER; EVOLUTION; MODEL; OXIDIZING SIDE; oxygen evolution; P680; PHOTOSYNTHETIC REACTION-CENTER; photosystem II; proton transfer; REACTION CENTER COMPLEX; redox potential; relaxation; TEMPERATURE; TOPOLOGY; water oxidation | Erscheinungsdatum: | 1999 | Herausgeber: | ELSEVIER SCIENCE BV | Journal: | BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS | Volumen: | 1410 | Ausgabe: | 1 | Startseite: | 1 | Seitenende: | 6 | Zusammenfassung: | Photosystem II (PSII) of green plants and cyanobacteria uses energy of light to oxidize water and to produce oxygen. The available estimates of the oxidizing potential of P-680(+), the primary donor of PSII, yield value of about 1.15 V. Two main factors are suggested to add up and engender this high oxidizing potential, namely: (1) the electrostatic influence dominated by Arg-181 of the D2 subunit which elevates the oxidizing potential of P680(+) up to 1 V, some 0.1 V above the E-m value of a hydrogen-bonded chlorophyll a; and (2) the dynamic component of 0.10-0.15 V due to the experimentally demonstrated retarded protonic relaxation at the P-680 site. (C) 1999 Elsevier Science B.V. All rights reserved. |
ISSN: | 00052728 | DOI: | 10.1016/S0005-2728(98)00174-1 |
Zur Langanzeige