Properties of the F₀F₁ ATPase Complex from Rhodospirillum rubrum Chromatophores, Solubilized by Triton X‐100

Abstract

A cold‐stable oligomycin‐sensitive F0F1 ATPase complex from chromatophores of Rhodospirillum rubrum FR 1 was solubilized by Triton X‐100 and purified by gel filtration. The F0F1 complex is resolved by sodium dodecyl sulfate electrophoresis into 14 polypeptides with approximate molecular weights in the range of 58000–6800; five of these polypeptides are derived from the F1 moiety of the complex which carries the catalytic centers of the enzyme. The purified F0F1 complex is homogeneous according to analytical ultracentrifugation and isoelectric focusing. The molecular weight as determined by gel filtration is about 480000 ± 30000. so20,w is 1.45 ± 0.1 S and the pI is 5.4. The amino acid composition of the F0F1 complex is compared with the data obtained for the F1 moiety of the enzyme. Quantitative data on the sensitivity to N,N′‐dicyclohexyl‐carbodiimide as well as kinetic parameters, regarding substrate specificity and dependence of ATPase activity on divalent cations, are reported.

Structure and function of proton-translocating adenosine triphosphatase (F0F1): biochemical and molecular biological approaches.

“…F0F1 of E. coli has also been prepared by other groups, but has not yet been characterized in detail (17,184). F0F1 has been prepared from R. rubrum (9,201), Clostridium pasteurianum (32), and Micrococcus luteus (199), although most preparations were not as well characterized as those from the thermophilic bacterium and E. coli. The Fo portion has been purified from E. coli (69, 157) and from thermophilic bacterium PS3 (165) in reconstitutively active forms.…”