(Mechanisms of photochemical energy conversion by chlorophyll): Progress report, July 1, 1986 to April 15, 1987

Technical Report · Thu Jan 01 00:00:00 EST 1987

OSTI ID:6802580

Tollin, G

Oxidized cytochrome c, when bound electrostatically to the surface of negatively-charged bilayer vesicles can function as an electron acceptor from chlorophyll triplet state. We have extended this type of experiment to plastocyanin bound to positively-charged bilayer vesicles. It was shown that plastocyanin is bound to egg phosphatidylcholine vesicles containing 5 to 25 mole percent dioctadecyldimethylammonium chloride (DODAC/sup +/) via electrostatic interactions in a 50 mM betaine medium (pH = 6.5). This was demonstrated by both gel filtration experiments and kinetic results using laser flash photolysis. Under those conditions, oxidized plastocyanin can function as a direct electron acceptor from membrane-bound triplet chlorophyll to produce chlorophyll cation radical and reduced plastocyanin. The fraction of chlorophyll triplet which is quenched by oxidized plastocyanin increases, and the yield of electron transfer products also increases, with an increase in the magnitude of the positive charge on the vesicles.

• Research Organization: Arizona Univ., Tucson (USA)
• DOE Contract Number: FG02-86ER13631
• OSTI ID: 6802580
• Report Number(s): DOE/ER/13631-1; ON: DE87009431
• Resource Relation: Other Information: Portions of this document are illegible in microfiche products
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
59 BASIC BIOLOGICAL SCIENCES
CHLOROPHYLL
ELECTRON TRANSFER
CYTOCHROMES
LIPOSOMES
CARBOXYLIC ACIDS
CELL CONSTITUENTS
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANOIDS
PHYTOCHROMES
PIGMENTS
PORPHYRINS
PROTEINS
140505* - Solar Energy Conversion- Photochemical
Photobiological
& Thermochemical Conversion- (1980-)
550200 - Biochemistry