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Titolo:
ELECTRON-TRANSFER DYNAMICS OF RHODOPSEUDOMONAS-VIRIDIS REACTION CENTERS WITH A MODIFIED BINDING-SITE FOR THE ACCESSORY BACTERIOCHLOROPHYLL
Autore:
ARLT T; DOHSE B; SCHMIDT S; WACHTVEITL J; LAUSSERMAIR E; ZINTH W; OESTERHELT D;
Indirizzi:
UNIV MUNICH,INST MED OPT,BARBARASTR 16 D-80797 MUNICH GERMANY UNIV MUNICH,INST MED OPT D-80797 MUNICH GERMANY MAX PLANCK INST BIOCHEM D-82152 MARTINSRIED GERMANY MAX PLANCK INST BIOPHYS,ABT MOLEK MEMBRANBIOL D-60528 FRANKFURT GERMANY
Titolo Testata:
Biochemistry
fascicolo: 28, volume: 35, anno: 1996,
pagine: 9235 - 9244
SICI:
0006-2960(1996)35:28<9235:EDORRC>2.0.ZU;2-N
Fonte:
ISI
Lingua:
ENG
Soggetto:
PHOTOSYNTHETIC REACTION-CENTER; BACTERIAL REACTION CENTERS; PRIMARY CHARGE SEPARATION; CYTOCHROME-C(2) MEDIATED REREDUCTION; L-SUBUNIT PLAYS; RHODOBACTER-SPHAEROIDES; PRIMARY DONOR; SPECTROSCOPY; MUTATIONS; KINETICS;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
53
Recensione:
Indirizzi per estratti:
Citazione:
T. Arlt et al., "ELECTRON-TRANSFER DYNAMICS OF RHODOPSEUDOMONAS-VIRIDIS REACTION CENTERS WITH A MODIFIED BINDING-SITE FOR THE ACCESSORY BACTERIOCHLOROPHYLL", Biochemistry, 35(28), 1996, pp. 9235-9244

Abstract

Femtosecond spectroscopy in combination with site-directed mutagenesis was used to study the influence of histidine L153 in primary electron transfer in the reaction center of Rhodopseudomas viridis. Histidinewas replaced by cysteine, glutamate, or leucine. The exchange to cysteine did not lead to significant changes in the primary reaction dynamics. In the case of the glutamate mutation, the decay of the excited electronic level of the special pair P is slowed by a factor of 3. Theexchange to leucine caused the incorporation of a bacteriopheophytin b instead of a bacteriochlorophyll b molecule at the B-A site, As a consequence of this chromophore exchange, the energy level of the electron transfer state P+BA- is lowered to such an extent that repopulationfrom the next electron transfer intermediate state P+HA- takes place,resulting in a long-lasting P+BA- population. The observed differences in time constants are discussed in the scope of nonadiabatic electron transfer theory considering the influence of the amino acids at position L153 and the chromophore exchange on the energy level of the intermediate state P+BA-. The results show that the high efficiency of primary electron transfer is reduced substantially, if the energy level of P+BA- is lowered or raised by several hundred wavenumbers.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 09/07/20 alle ore 17:19:29