Stoichiometry of the H+‐ATPase of Escherichia coli cells during anaerobic growth

FEBS Letters

Kashket, Eva R.¹ 

[1] Department of Microbiology, Boston University School of Medicine, Boston, MA 02118, USA

关键词: H+-ATPase;    Proton motive force;    Escherichia coli;    Phosphorylation potential Anaerobiosis;    Stoichiometry;    EDTA;    ethylenediaminetetraacetic acid;    TPP+;    tetraphenylphosphonium ion;    Tris;    tris(hydroxymethyl)aminomethane;    XDP;    xanthosine diphosphate;    PMF or Δp;    protonmotive force = Δψ − Z ΔpH = Δ≈μH + /F;    Δψ;    transmembrane electrical gradient;    ΔpH;    transmembrane chemical gradient of H+ = pHout (pH of the bulk medium)-pHin (pH of the cytosol);    Δp lac;    Δμ lac /F;    ΔG′p;    phosphorylation potential = Gibbs free energy of ATP synthesis = ΔG′0 + RT ln[ATP]/[ADP][Pi];    ΔG′0;    standard free energy of ATP hydrolysis;   

DOI  :  10.1016/0014-5793(83)80179-3

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The H⁺/ATP stoichiometry of the H⁺-ATPase was investigated in Escherichia coli cells growing under anaerobic conditions at pH 6 and 7. The protonmotive force was determined from the intracellular accumulation of benzoate and tetraphenylphosphonium ions, as well as the accumulation of lactose in this lac operon inducible, but β-galactosidase negative strain. The phosphorylation potential was calculated from the cellular concentrations of ATP, ADP and inorganic phosphate. By comparing the phosphorylation potential and the proton motive force under these steady state conditions, the H⁺/ATP stoichiometry was determined to be 3, similar to the value previously found in the same cells growing under aerobic conditions.

【 授权许可】

Unknown