Transverse topography of the photochemical reaction center polypeptides in the Rhodopseudomonas capsulata membrane
The exposure of the three polypeptide subunits H, M, and L of the photochemical reaction center (RC) on both surfaces of the membrane of Rhodopseudomonas capsulata was studied by partial proteolysis with proteinase K and sodium dodecyl sulfate-polyacrylamide gel electrophoresis of degradation products. The possible association of RC subunits with bacteriochlorophyll a and bacteriopheophytin was investigated by spectroscopical measurements. Chromatophores (inside-out oriented) and spheroplasts (right-side-out oriented), as well as purified, detergent-solubilized RCs and RCs reconstituted into phosphatidyl choline liposomes, were used. Subunit H of the RC was degraded to fragments with apparent M/sub r/s of 15,000 and 12,500 which were possibly derived from cleavage of a loop exposed on the cytoplasmic surface. Polypeptide M was digested at a comparable rate. The apparent M/sub r/ of M decreased by roughly 4000 upon proteolytic cleavage. Subunit L was relatively insensitive to protease attach, except that a small peptide was clipped off. The primary donor P870 was also found to be only slightly affected by proteinase K. All three RC subnunits appear to be exposed on the chromatophore surface.
- Research Organization:
- Albert-Ludwigs-Univ., Freiburg, West Germany
- OSTI ID:
- 6004295
- Journal Information:
- J. Bacteriol.; (United States), Vol. 158:3
- Country of Publication:
- United States
- Language:
- English
Similar Records
Nucleotide and deduced polypeptide sequences of the photosynthetic reaction-center, B870 antenna, and flanking polypeptides from R. capsulata
Gene expression of pigment-binding proteins of the bacterial photosynthetic apparatus: transcription and assembly in the membrane of Rhodopseudomonas capsulata
Related Subjects
14 SOLAR ENERGY
PHOTOSYNTHETIC BACTERIA
BIOLOGY
POLYPEPTIDES
STRUCTURAL CHEMICAL ANALYSIS
CHLOROPHYLL
CYTOPLASM
LIPOSOMES
PHOTOCHEMISTRY
PHOTOSYNTHETIC REACTION CENTERS
PROTEOLYSIS
SPECTROSCOPY
CARBOXYLIC ACIDS
CELL CONSTITUENTS
CHEMICAL REACTIONS
CHEMISTRY
DECOMPOSITION
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANOIDS
PEPTIDES
PHYTOCHROMES
PIGMENTS
PORPHYRINS
PROTEINS
550700* - Microbiology
140505 - Solar Energy Conversion- Photochemical
Photobiological
& Thermochemical Conversion- (1980-)