Heterogeneity of photosynthetic membranes from Rhodobacter capsulatus: Size dispersion and ATP synthase distribution

Autor: Francesco Francia, Paola Turina, Giovanni Venturoli, Francesca Gubellini, B. Andrea Melandri, Daniel Lévy
Přispěvatelé: Alma Mater Studiorum Università di Bologna [Bologna] (UNIBO), Physico-Chimie-Curie (PCC), Centre National de la Recherche Scientifique (CNRS)-Institut Curie [Paris]-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC), Consorzio Nazionale Interuniversitario per le Scienze FIsiche della Materia (CNISM), This research was supported by the Italian Ministry of Education and Research (MIUR) (PRIN Project 'Meccanismi molecolari e aspetti fisiopatologici dei sistemi bioenergetici di membrana.', number 2005052128_004). F.G was supported by the European Community (IHP-RTN) and the Human Frontier Science Program., Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut Curie [Paris]-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Gubellini F., Francia F., Turina P., Lévy D., Venturoli G., Melandri B.A.
Jazyk: angličtina
Rok vydání: 2007
Předmět:
Sucrose
Light
ATPase
MESH: Bacterial Chromatophores
Intracytoplasmic membrane
Biochemistry
Rhodobacter capsulatus
Adenosine Triphosphate
MESH: Centrifugation
Density Gradient
MESH: Spectrophotometry
Ultraviolet
MESH: Adenosine Triphosphate
Scattering
Radiation
Phosphorylation
0303 health sciences
Rhodobacter
ATP synthase
biology
MESH: Kinetics
[SDV.BBM.BS]Life Sciences [q-bio]/Biochemistry
Molecular Biology/Structural Biology [q-bio.BM]
MESH: Peptides
Hydrolysis
030302 biochemistry & molecular biology
Efrapeptin
Bacterial Chromatophores
ATP synthase alpha/beta subunits
MESH: Hydrolysis
[PHYS.PHYS.PHYS-BIO-PH]Physics [physics]/Physics [physics]/Biological Physics [physics.bio-ph]
Blotting
Western
Biophysics
Photophosphorylation
MESH: Microscopy
Electron
[SDV.BC]Life Sciences [q-bio]/Cellular Biology
03 medical and health sciences
MESH: Bacterial Proton-Translocating ATPases
Centrifugation
Density Gradient
[CHIM.CRIS]Chemical Sciences/Cristallography
MESH: Blotting
Western
[SDV.BBM]Life Sciences [q-bio]/Biochemistry
Molecular Biology
MESH: Scattering
Radiation
030304 developmental biology
MESH: Phosphorylation
Chemiosmosis
MESH: Sucrose
Cell Biology
Size distribution
biology.organism_classification
Carotenoids
MESH: Light
MESH: Rhodobacter capsulatus
Kinetics
Microscopy
Electron
Bacterial Proton-Translocating ATPases
MESH: Carotenoids
biology.protein
Photosynthetic membrane
Spectrophotometry
Ultraviolet
Heterogeneity
[INFO.INFO-BI]Computer Science [cs]/Bioinformatics [q-bio.QM]
Peptides
Zdroj: Biochimica biophysica acta (BBA)-Bioenergetics
Biochimica biophysica acta (BBA)-Bioenergetics, Elsevier, 2007, 1767 (11), pp.1340-1352. ⟨10.1016/j.bbabio.2007.08.007⟩
Biochimica biophysica acta (BBA)-Bioenergetics, 2007, 1767 (11), pp.1340-1352. ⟨10.1016/j.bbabio.2007.08.007⟩
ISSN: 0005-2728
1879-2650
DOI: 10.1016/j.bbabio.2007.08.007⟩
Popis: International audience; The density distribution of photosynthetic membrane vesicles (chromatophores) from Rhodobacter capsulatus has been studied by isopicnic centrifugation. The average vesicle diameters, examined by electron microscopy, varied between 61 and 72 nm in different density fractions (70 nm in unfractionated chromatophores). The ATP synthase catalytic activities showed maxima displaced toward the higher density fractions relative to bacteriochlorophyll, resulting in higher specific activities in those fractions (about threefold). The amount of ATP synthase, measured by quantitative Western blotting, paralleled the catalytic activities. The average number of ATP synthases per chromatophore, evaluated on the basis of the Western blotting data and of vesicle density analysis, ranged between 8 and 13 (10 in unfractionated chromatophores). Poisson distribution analysis indicated that the probability of chromatophores devoid of ATP synthase was negligible. The effects of ATP synthase inhibition by efrapeptin on the time course of the transmembrane electric potential (evaluated as carotenoid electrochromic response) and on ATP synthesis were studied comparatively. The ATP produced after a flash and the total charge associated with the proton flow coupled to ATP synthesis were more resistant to efrapeptin than the initial value of the phosphorylating currents, indicating that several ATP synthases are fed by protons from the same vesicle.
Databáze: OpenAIRE
Externí odkaz: