ENDOR studies of the intermediate electron acceptor radical anion I-. in Photosystem II reaction centers.
Biochim Biophys Acta
; 977(2): 227-32, 1989 Nov 23.
Article
em En
| MEDLINE
| ID: mdl-2553112
ABSTRACT
The EPR and ENDOR characteristics of the intermediate electron acceptor radical anion I-. in Photosystem II (PS II) are shown to be identical in membrane particles and in the D1D2 cytochrome b-559 complex (Nanba, O. and Satoh, K. (1987) Proc. Natl. Acad. Sci. USA 84, 109-112). These findings provide further evidence that the D1D2 complex is the reaction center of PS II and show that the pheophytin binding site is intact. A hydrogen bond between I-. and the protein (GLU D1-130) is postulated on the basis of D2O exchange experiments. The ENDOR data of I-. and of the pheophytin a radical anion in different organic solvents are compared and the observed differences are related to structural changes of the molecule on the basis of molecular orbital calculations (RHF-INDO/SP). The importance of the orientation of the vinyl group (attached to ring I) on electron transfer is discussed.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas de Plantas
/
Clorofila
/
Complexo de Proteína do Fotossistema II
/
Ânions
Idioma:
En
Revista:
Biochim Biophys Acta
Ano de publicação:
1989
Tipo de documento:
Article
País de afiliação:
Alemanha