Annual progress report, December 1, 1979-November 30, 1980
Structure and function in photosynthetic membranes and their components continue to be studied, principally with Rhodopseudomonas sphaeroides. We have discovered how to remove bacteriochlorophyll (bchl) from a specific binding site in the antenna pigment-protein complex B850, and to replace the bchl without denaturing the complex. This has never before been achieved for any photosynthetic chlorophyllprotein complex. It opens a substantial vista of experiments designed to elucidate the nature of the binding site. Our analyses of the B850 and B875 complexes cast doubt on the accepted ratios of bchl components, carotenoids and protein and hence on models based on these ratios. We have shown that Rp. sphaeroides contains a specific second quinone (Q/sub b/) in contact with the primary photochemical electron acceptor (Q/sub a/) and distinct from the molecules of a larger pool of quinone. We have resolved conflicting reports about the polypeptide composition of reaction centers from Rhodopseudomonas viridis. We have new data on the orientation, relative to the photosynthetic membrane, of cytochrome 552 in Rp. viridis and of the shifting component of carotenoid in Rp. sphaeroides. We have constructed and are using a new circular dichroism spectrometer.
- Research Organization:
- Cornell Univ., Ithaca, NY (USA)
- DOE Contract Number:
- AS02-76ER03162
- OSTI ID:
- 6702659
- Report Number(s):
- COO-3162-53; COO-3162-54(App.B)
- Country of Publication:
- United States
- Language:
- English
Similar Records
(Structure and function in photosynthetic membranes and their components). Annual progress report, December 1, 1978-November 30, 1979
Isolation and characterization of the pigment-protein complexes of Rhodopseudomonas sphaeroides by lithium dodecyl sulfate/polyacrylamide gel electrophoresis
Related Subjects
59 BASIC BIOLOGICAL SCIENCES
BACTERIA
CARBOXYLIC ACIDS
CAROTENOIDS
CELL CONSTITUENTS
CELL MEMBRANES
CHEMICAL BONDS
CHEMICAL REACTIONS
CHLOROPHYLL
COMPLEXES
CYTOCHROMES
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
HYDROCARBONS
MEMBRANES
MICROORGANISMS
MOLECULAR STRUCTURE
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHOTOSYNTHESIS
PHOTOSYNTHETIC BACTERIA
PHYTOCHROMES
PIGMENTS
PORPHYRINS
PROTEINS
RESEARCH PROGRAMS
RHODOPSEUDOMONAS
SYNTHESIS
TERPENES