Kinetics of charge separation and A(0)(-)-> A(1) electron transfer in photosystem reaction centers

Citation
S. Savikhin et al., Kinetics of charge separation and A(0)(-)-> A(1) electron transfer in photosystem reaction centers, BIOCHEM, 40(31), 2001, pp. 9282-9290
Citations number
39
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Biochemistry & Biophysics
Journal title
BIOCHEMISTRY
ISSN journal
0006-2960 → ACNP
Volume
40
Issue
31
Year of publication
2001
Pages
9282 - 9290
Database
ISI
SICI code
0006-2960(20010807)40:31<9282:KOCSAA>2.0.ZU;2-V
Abstract
The charge separation P700*A(0) --> P700(+)A(0)(-) and the subsequent elect ron transfer from the primary to secondary electron acceptor have been stud ied by subtracting absorption difference profiles for cyanobacterial photos ystem I (PS I) complexes with open and closed reaction centers. Samples wer e excited at 660 run, which lies toward the blue edge of the core antenna a bsorption spectrum. The resulting PS I kinetics were analyzed in terms of t he relevant P700, P700(+), A(0), and A(0)(-) absorption spectra. In our kin etic model, the radical pair P700+A(0)(-) forms with 1.3 ps rise kinetics a fter creation of electronically excited P700*. The formation of A(1)(-) via electron transfer from A(0) requires similar to 13 ps. The kinetics of the latter step are appreciably faster than previously estimated by other grou ps (20-50 ps).