Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
Modeling the bacterial photosynthetic reaction center 3: Interpretation ofeffects of site-directed mutagenesis on the special-pair midpoint potential
Autore:
Reimers, JR; Hughes, JM; Hush, NS;
Indirizzi:
Univ Sydney, Sch Chem, Sydney, NSW 2006, Australia Univ Sydney Sydney NSWAustralia 2006 h Chem, Sydney, NSW 2006, Australia Univ Sydney, Dept Biochem, Sydney, NSW 2006, Australia Univ Sydney SydneyNSW Australia 2006 iochem, Sydney, NSW 2006, Australia
Titolo Testata:
BIOCHEMISTRY
fascicolo: 51, volume: 39, anno: 2000,
pagine: 16185 - 16189
SICI:
0006-2960(200012)39:51<16185:MTBPRC>2.0.ZU;2-U
Fonte:
ISI
Lingua:
ENG
Soggetto:
PRIMARY ELECTRON-DONOR; RHODOBACTER-SPHAEROIDES; RADICAL CATIONS; PHOTOSYSTEM-II; ENERGY COMPUTATIONS; PURPLE BACTERIA; MIXED-VALENCE; SPECTROSCOPY; RESONANCE; COFACTORS;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
29
Recensione:
Indirizzi per estratti:
Indirizzo: Hush, NS Univ Sydney, Sch Chem, Sydney, NSW 2006, Australia Univ Sydney Sydney NSW Australia 2006 ydney, NSW 2006, Australia
Citazione:
J.R. Reimers et al., "Modeling the bacterial photosynthetic reaction center 3: Interpretation ofeffects of site-directed mutagenesis on the special-pair midpoint potential", BIOCHEM, 39(51), 2000, pp. 16185-16189

Abstract

Interpretation of changes in midpoint potential of the "special pair" in bacterial photosynthetic reaction centers caused by site-directed mutagenesis is discussed in terms of a simple tight-binding model which relates them to concomitant variations in spin distribution between the two bacteriochlorophyll molecules of the special pair. Our analysis improves on previous similar ones by Alien and co-workers [Artz, K., Williams, J. C., Allen, J. P., Lendzian, F., Rautter, J., and Lubitz, W. (1997) Proc. Nad Acad. Sci. U.S. A. 94, 13582; Ivancich, A., Artz, K., Williams, J. C., Alien, J. P., and Mattioli, T. A. (1998) Biochemistry 37, 11812] in that it is both more complete, including electron-phonon coupling, and more accurate. It is applied to analyze data for a series of M160 mutants of Rhodobacter sphaeroides, yielding a value of 0.18 +/- 0.03 eV for the electronic coupling energy between the highest occupied levels of the two bacteriochlorophylls in the wild-type and a value of the energy offset E-o between the highest occupied molecular orbitals of the L and M bacteriochlorophylls of 0.14 +/- 0.03 eV. For a mutant in which the electron hole in the special pair cation is located entirely on the reactive (L) side, a potential of 641 +/- 30 mV with respectto the normal hydrogen electrode is predicted. This agrees well with the average value ca. 650 mV observed for the heterodimer mutant HL(M202) in which the bacteriochlorophyll on the unreactive M side has been replaced by a bacteriopheophytin, causing extensive charge localization. However, the deduced coupling is found to be very sensitive to small changes in the assumptions used in the model, and various important chemical effects remain to beincluded.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 24/11/20 alle ore 10:54:29