ATP synthesis at physiological nucleotide concentrations.

Meyrat, Axel; von Ballmoos, Christoph (2019). ATP synthesis at physiological nucleotide concentrations. Scientific reports, 9(1), p. 3070. Springer Nature 10.1038/s41598-019-38564-0

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Synthesis of ATP by the F1F0 ATP synthase in mitochondria and most bacteria is energized by the proton motive force (pmf) established and maintained by respiratory chain enzymes. Conversely, in the presence of ATP and in the absence of a pmf, the enzyme works as an ATP-driven proton pump. Here, we investigate how high concentrations of ATP affect the enzymatic activity of the F1F0 ATP synthase under high pmf conditions, which is the typical situation in mitochondria or growing bacteria. Using the ATP analogue adenosine 5'-O-(1-thiotriphosphate) (ATPαS), we have developed a modified luminescence-based assay to measure ATP synthesis in the presence of millimolar ATP concentrations, replacing an assay using radioactive nucleotides. In inverted membrane vesicles of E. coli, we found that under saturating pmf conditions, ATP synthesis was reduced to ~10% at 5 mM ATPαS. This reduction was reversed by ADP, but not Pi, indicating that the ATP/ADP ratio controls the ATP synthesis rate. Our data suggests that the ATP/ADP ratio ~30 in growing E. coli limits the ATP synthesis rate to ~20% of the maximal rate possible at the applied pmf and that the rate reduction occurs via product inhibition rather than an increased ATP hydrolysis rate.

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Department of Chemistry, Biochemistry and Pharmaceutical Sciences (DCBP)

Graduate School:

Graduate School for Cellular and Biomedical Sciences (GCB)

UniBE Contributor:

Meyrat, Axel Alexandre and von Ballmoos, Christoph

Subjects:

500 Science > 570 Life sciences; biology
500 Science > 540 Chemistry

ISSN:

2045-2322

Publisher:

Springer Nature

Language:

English

Submitter:

Axel Alexandre Meyrat

Date Deposited:

02 Nov 2020 12:11

Last Modified:

13 Mar 2021 11:51

Publisher DOI:

10.1038/s41598-019-38564-0

PubMed ID:

30816129

BORIS DOI:

10.7892/boris.129394

URI:

https://boris.unibe.ch/id/eprint/129394

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