Characterization of a purified photosystem II-phycobilisome particle preparation from Porphyridium cruentum
Detergent preparations isolated from thylakoids of the red alga Porphyridium cruentum, in a sucrose, phosphate, citrate, magnesium chloride medium consist of phycobilisomes and possess high rates of photosystem II activity. Characterization of these particles shows that the O/sub 2/-evolving activity is stable for several hours and the pH optimum is about 6.5 to 7.2. Response of the system to light, electron donors and acceptors, and inhibitors verify that the observed activity, measured both as O/sub 2/ evolution and 2,6-dichlorophenol-indophenol reduction, is due to photosystem II. Furthermore, photosystem II is functionally coupled to the phycobilisome in this preparation since green light, absorbed by phycobilisomes of P. cruentum, is effective in promoting both O/sub 2/ evolution and 2,6-dichlorophenol-indophenol reduction. Photosystem II activity declines when light with wavelengths shorter than 665 nm is removed. Both 3-(3,4-dichlorophenyl)-1,1-dimethylurea and atrazine inhibit photosystem II activity in this preparation, indicating that the herbicide binding site is a component of the photosystem II-phycobilisome particle. 24 references, 4 figures, 2 tables.
- Research Organization:
- Smithsonian Environmental Research Center, Rockville, MD
- DOE Contract Number:
- AS05-76ER04310
- OSTI ID:
- 5944309
- Journal Information:
- Plant Physiol.; (United States), Vol. 77
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
14 SOLAR ENERGY
ALGAE
PHOTOSYNTHETIC REACTION CENTERS
PHOTOSYNTHESIS
BIOCHEMICAL REACTION KINETICS
PHYCOBILISOMES
PURIFICATION
RECEPTORS
HERBICIDES
OXYGEN
CELL CONSTITUENTS
CHEMICAL REACTIONS
ELEMENTS
KINETICS
MEMBRANE PROTEINS
NONMETALS
ORGANIC COMPOUNDS
PESTICIDES
PHOTOCHEMICAL REACTIONS
PLANTS
PROTEINS
REACTION KINETICS
SYNTHESIS
550200* - Biochemistry
140505 - Solar Energy Conversion- Photochemical
Photobiological
& Thermochemical Conversion- (1980-)