Isolation and characterization of the pigment-protein complexes of Rhodopseudomonas sphaeroides by lithium dodecyl sulfate/polyacrylamide gel electrophoresis

Journal Article · Tue Jan 01 00:00:00 EST 1980 · Proc. Natl. Acad. Sci. U.S.A.; (United States)

DOI:https://doi.org/10.1073/pnas.77.1.87· OSTI ID:5292844

Broglie, R M ^[1]; Hunter, C N; Delepelaire, P; Niederman, R A; Chua, N H; Clayton, R K

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1. Rutgers Univ., New Brunswick, NJ

When purified photosynthetic membranes from Rhodopseudomonas sphaeroides were treated with lithium dodecyl sulfate and subjected to polyacrylamide gel electrophoresis at 4/sup 0/C, up to 11 pigment-protein complexes were resolved. Absorption spectra revealed that the smallest complex contained reaction center pigments and the others contained the antenna components B850 and B875 in various proportions. Of these antenna complexes, the largest was almost entirely B850 and the smallest contained only B875. After solubilization at 100/sup 0/C and electrophoresis on polyacrylamide gradient gels, the B850 complex gave rise to two polypeptide components migrating with apparent M/sub r/ of 10,000 and 8000, whereas with the B875 complex, two components were observed with apparent M/sub r/ of 12,000 and 8000. The reaction center complex gave rise to only the 24 and 21 kilodalton polypeptide subunits. Fluorescence emission spectra showed maxima at 872 and 902 nm for B850 and B875, respectively. Analyses of bacteriochlorophyll a and carotenoids indicated that, in the B875 complex, two molecules of each of these pigments are associated with the two polypeptides. The associations of B850 and B875 in large and small complexes obtained by lithium dodecyl sulfate treatment are consistent with models of their organization within the membrane.

• OSTI ID: 5292844
• Journal Information: Proc. Natl. Acad. Sci. U.S.A.; (United States), Vol. 77:1
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
CAROTENOIDS
SEPARATION PROCESSES
RHODOPSEUDOMONAS
PHOTOSYNTHESIS
CELL MEMBRANES
CHEMICAL PREPARATION
ELECTROPHORESIS
FLUORESCENCE SPECTROSCOPY
BACTERIA
CELL CONSTITUENTS
CHEMICAL REACTIONS
EMISSION SPECTROSCOPY
HYDROCARBONS
MEMBRANES
MICROORGANISMS
ORGANIC COMPOUNDS
PHOTOCHEMICAL REACTIONS
PIGMENTS
SPECTROSCOPY
SYNTHESIS
TERPENES
550200* - Biochemistry
550700 - Microbiology