Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Primary light harvesting system: the relationship of phycobilisomes to photosystem I and II. Progress report, September 1983-March 1984

Technical Report ·
OSTI ID:6204640
It has long been known that energy absorbed by phycobiliproteins is transferred to photosystem II and is then distributed to I. Consequently, it has been predicted that phycobilisomes would be in close association with photosystem II. Our laboratory has succeeded in isolating phycobilisomes which have photosystem II activity, as measured by oxygen evolution, and reduction of dichlorophenol indophenol. In a special medium (0.5 M phosphate buffer, 0.5 M sucrose, 0.3 M citrate, and 10 mM magnesium chloride) the phycobilisomes remain intact, and the PS II activity is preserved. These preparations are deficient in the PS I reaction center pigment P700, as well as in the PS I polypeptide CP 1. Preparations of this system are being further characterized to determine the P680 content, to ascertain the DCMU-binding protein, cytochromes, and other polypeptides which are specific for PS II, and also for PS I. In addition, the sidedness of thylakoid membranes of red algae and cyanobacteria are also being explored by immunocytochemistry (EM) and fractionation on acrylamide gels. Attachment of the phycobilisomes, and the location of the terminal emitter of phycobilisomes, are an integral part of these studies. Results from these studies will aid in our understanding of the energy transfer in the photosynthetic apparatus of these groups of organisms which appear to have a considerable convergence from green plants.
Research Organization:
Smithsonian Institution, Rockville, MD (USA). Smithsonian Environmental Research Center
DOE Contract Number:
AS05-76ER04310
OSTI ID:
6204640
Report Number(s):
DOE/ER/04310-T2; ON: DE85003075
Country of Publication:
United States
Language:
English