6533b871fe1ef96bd12d193c

RESEARCH PRODUCT

Pump and Displacement Currents of Reconstituted ATP Synthase on Black Lipid Membranes

Klaus DoseM. GutweilerB. ChristensenErnst GrellN. WagnerErnst BambergRainer Pabst

subject

OligomycinbiologyATP synthaseChemistryChemiosmosisStereochemistryVesicleRhodospirillum rubrumSynthetic membraneBacteriorhodopsinbiology.organism_classificationchemistry.chemical_compoundbiology.proteinBiophysicsATP synthase alpha/beta subunits

description

Purified ATP synthase (F0F1) from Rhodospirillum rubrum was reconstituted into asolectine liposomes which were then adsorbed to a planar lipid bilayer. After the addition of an inactive photolabile ATP derivative (caged ATP), ATP was released after illumination with u.v.-light, which led to a transient current in the system. The transient photocurrent indicates that the vesicles and the planar membrane are capacitatively coupled. Stationary pump currents were obtained after addition of protonophores. These currents are specifically inhibited by oligomycin and stimulated threefold by inorganic phosphate (Pi). In analogy oligomycin sensitive pump currents in the reverse direction coupled to net ATP synthesis were induced by a light-induced concentration jump of ADP out of caged ADP, demonstrating the reversibility of the pump. For this, a preformed proton motive force and Pi were necessary.

yearjournalcountryeditionlanguage
1988-01-01
https://doi.org/10.1007/978-94-009-3075-9_36