Observations of rotation within the FoF1‐ATP synthase: deciding between rotation of the Fo c subunit ring and artifact

FEBS Letters

Noji, Hiroyuki¹  Tsunoda, Satoshi P.²  Capaldi, Roderick A.³  Aggeler, Robert³  Yoshida, Masasuke²  Kinosita, Kazuhiko¹ 

[1] CREST (Core Research for Evolutional Science and Technology) Genetic Programming Team 13, Teikyo University Biotechnology Research Center 3F, 907 Nogawa, Miyamae, Kawasaki 216-0001, Japan;Research Laboratory of Resources Utilization, Tokyo Institute of Technology, 4259 Nagatsuta, Yokohama 226-8503, Japan;Institute of Molecular Biology, University of Oregon, Eugene, OR 97403-1229, USA

关键词: FoF1-ATP synthase;    Rotation;    c subunit ring;    Detergent;    Uncoupling;    BM;    biotin-PEAC5-maleimide;    FM;    fluorescein-5-maleimide;    DCCD;    dicyclohexylcarbodiimide;   

DOI  :  10.1016/S0014-5793(00)01336-3

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

F_oF₁-ATP synthase mediates coupling of proton flow in F_o and ATP synthesis/hydrolysis in F₁ through rotation of central rotor subunits. A ring structure of F_o c subunits is widely believed to be a part of the rotor. Using an attached actin filament as a probe, we have observed the rotation of the F_o c subunit ring in detergent-solubilized F_oF₁-ATP synthase purified from Escherichia coli. Similar studies have been performed and reported recently [Sambongi et al. (1999) Science 286, 1722–1724]. However, in our hands this rotation has been observed only for the preparations which show poor sensitivity to dicyclohexylcarbodiimde, an F_o inhibitor. We have found that detergents which adequately disperse the enzyme for the rotation assay also tend to transform F_oF₁-ATP synthase into an F_o inhibitor-insensitive state in which F₁ can hydrolyze ATP regardless of the state of the F_o. Our results raise the important issue of whether rotation of the F_o c ring in isolated F_oF₁-ATP synthase can be demonstrated unequivocally with the approach adopted here and also used by Sambongi et al.

【 授权许可】

Unknown