Steady-State Proton Translocation in Bovine Heart Mitochondrial bc1 Complex Reconstituted into Liposomes
- 1 January 1997
- journal article
- Published by Springer Nature in Journal of Bioenergetics and Biomembranes
- Vol. 29 (1) , 81-87
- https://doi.org/10.1023/a:1022467923837
Abstract
The effect of different anions on the steady-state proton translocation in bovine bc1 complex reconstituted in liposomes was studied. The H+/e− ratio for vectorial proton translocation is at the steady state definitely lower than that measured at level flow, (0.3 vs. 1.0). The presence of azide or arachidonate at micro- and submicromolar concentrations, respectively, gave a substantial reactivation of the proton pumping activity at the steady state, without any appreciable effect on respiration-dependent transmembrane pH difference. Addition of azide to turning-over bc1 vesicles also caused a transition of b cytochromes toward oxidation. The results are discussed in terms of possible involvement of an acidic residue in the protonation of the semiquinone/quinol couple at the N side of the membrane.Keywords
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