Fusion of liposomones and chromatophores of Rhodopseudomonas capsulata: effect on photosynthetic energy transfer between B875 and reaction center complexes

Journal Article · Sat Jun 01 04:00:00 EDT 1985 · J. Bacteriol.; (United States)

OSTI ID:5093341

Takemoto, J Y; Schonhardt, T; Golecki, J R; Drews, G

The photosynthetic chromatophore membranes of Rhodopseudomonas capsulata were fused with liposomes to investigate the effects of lipid dilution on energy transfer between the bacteriochlorophyll-protein complexes of this membrane. Freeze-fracture electron microscopy revealed that the fractions contained closed vesicles formed by the fusion of liposomes to chromatophores. Particles with 9-nm diameters on the P fracture faces did not appear to change in size with increasing lipid content, but the number of particles per membrane area decreased proportionally with increases in the lipid-to-protein ratio. The bacteriochlorophyll-to-protein ratios, electrophoretic polypeptide profiles on sodium dodecyl sulfate-polyacrylamide gels, and light-induced absorbance changes at 595 nm caused by photosynthetic reaction centers were not altered by fusion. The relative fluorescence emission intensities due to the B875 light-harvesting complex increased significantly with increasing lipid content, but no increases in fluorescence due to the B800-B850 light-harvesting complex were observed. Electron transport rates, measured as succinate-cytochrome c reductase activities, decreased with increased lipid content. The results indicate an uncoupling of energy transfer between the B875 light-harvesting and reaction center complexes with lipid dilution of the chromatophore membrane.

• Research Organization: Utah State Univ., Logan
• OSTI ID: 5093341
• Journal Information: J. Bacteriol.; (United States), Journal Name: J. Bacteriol.; (United States) Vol. 162:3; ISSN JOBAA
• Country of Publication: United States
• Language: English

Related Subjects

550200 -- Biochemistry
550700* -- Microbiology
59 BASIC BIOLOGICAL SCIENCES
BACTERIA
BIOCHEMISTRY
CELL CONSTITUENTS
CHEMISTRY
ELECTRON MICROSCOPY
ENERGY TRANSFER
FREEZING
LIPOSOMES
MEMBRANES
MICROORGANISMS
MICROSCOPY
ORGANOIDS
PHOTOSYNTHETIC MEMBRANES
PHOTOSYNTHETIC REACTION CENTERS
RHODOPSEUDOMONAS