ISSN:
0730-2312
Schlagwort(e):
Chloroflexus aurantiacus
;
primary photochemistry
;
reaction centers
;
bacterial reaction centers
;
bacteriochlorophyll
;
bacteriopheophytin
;
menaquinone
;
ubiquinone
;
Life and Medical Sciences
;
Cell & Developmental Biology
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Biologie
,
Chemie und Pharmazie
,
Medizin
Notizen:
The mechanism of primary photochemistry has been investigated in purified cytoplasmic membranes and isolated reaction centers of Chloroflexus aurantiacus. Redox titrations on the cytoplasmic membranes indicate that the midpoint redox potential of P870, the primary electron donor bacteriochlorophyll, is +362 mV. An early electron acceptor, presumably menaquinone has Em 8.1 = -50 mV, and a tightly bound photooxidizable cytochrome c554 has Em 8.1 = +245 mV. The isolated reaction center has a bacteriochlorophyll to bacteriopheophytin ratio of 0.94:1. A two-quinone acceptor system is present, and is inhibited by o-phenanthroline. Picosecond transient absorption and kinetic measurements indicate the bacteriopheophytin and bacteriochlorophyll form an earlier electron acceptor complex.
Zusätzliches Material:
6 Ill.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/jcb.240220407
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