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Mechanism of ADP-Inhibited ATP Hydrolysis in Single Proton-Pumping F(o)F(1)-ATP Synthase Trapped in Solution
F(o)F(1)-ATP synthases in mitochondria, in chloroplasts, and in most bacteria are proton-driven membrane enzymes that supply the cells with ATP made from ADP and phosphate. Different control mechanisms exist to monitor and prevent the enzymes’ reverse chemical reaction of fast wasteful ATP hydrolysi...
Autores principales: | , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
MDPI
2023
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10178918/ https://www.ncbi.nlm.nih.gov/pubmed/37176150 http://dx.doi.org/10.3390/ijms24098442 |
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author | Pérez, Iván Heitkamp, Thomas Börsch, Michael |
author_facet | Pérez, Iván Heitkamp, Thomas Börsch, Michael |
author_sort | Pérez, Iván |
collection | PubMed |
description | F(o)F(1)-ATP synthases in mitochondria, in chloroplasts, and in most bacteria are proton-driven membrane enzymes that supply the cells with ATP made from ADP and phosphate. Different control mechanisms exist to monitor and prevent the enzymes’ reverse chemical reaction of fast wasteful ATP hydrolysis, including mechanical or redox-based blockade of catalysis and ADP inhibition. In general, product inhibition is expected to slow down the mean catalytic turnover. Biochemical assays are ensemble measurements and cannot discriminate between a mechanism affecting all enzymes equally or individually. For example, all enzymes could work more slowly at a decreasing substrate/product ratio, or an increasing number of individual enzymes could be completely blocked. Here, we examined the effect of increasing amounts of ADP on ATP hydrolysis of single Escherichia coli F(o)F(1)-ATP synthases in liposomes. We observed the individual catalytic turnover of the enzymes one after another by monitoring the internal subunit rotation using single-molecule Förster resonance energy transfer (smFRET). Observation times of single FRET-labeled F(o)F(1)-ATP synthases in solution were extended up to several seconds using a confocal anti-Brownian electrokinetic trap (ABEL trap). By counting active versus inhibited enzymes, we revealed that ADP inhibition did not decrease the catalytic turnover of all F(o)F(1)-ATP synthases equally. Instead, increasing ADP in the ADP/ATP mixture reduced the number of remaining active enzymes that operated at similar catalytic rates for varying substrate/product ratios. |
format | Online Article Text |
id | pubmed-10178918 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2023 |
publisher | MDPI |
record_format | MEDLINE/PubMed |
spelling | pubmed-101789182023-05-13 Mechanism of ADP-Inhibited ATP Hydrolysis in Single Proton-Pumping F(o)F(1)-ATP Synthase Trapped in Solution Pérez, Iván Heitkamp, Thomas Börsch, Michael Int J Mol Sci Article F(o)F(1)-ATP synthases in mitochondria, in chloroplasts, and in most bacteria are proton-driven membrane enzymes that supply the cells with ATP made from ADP and phosphate. Different control mechanisms exist to monitor and prevent the enzymes’ reverse chemical reaction of fast wasteful ATP hydrolysis, including mechanical or redox-based blockade of catalysis and ADP inhibition. In general, product inhibition is expected to slow down the mean catalytic turnover. Biochemical assays are ensemble measurements and cannot discriminate between a mechanism affecting all enzymes equally or individually. For example, all enzymes could work more slowly at a decreasing substrate/product ratio, or an increasing number of individual enzymes could be completely blocked. Here, we examined the effect of increasing amounts of ADP on ATP hydrolysis of single Escherichia coli F(o)F(1)-ATP synthases in liposomes. We observed the individual catalytic turnover of the enzymes one after another by monitoring the internal subunit rotation using single-molecule Förster resonance energy transfer (smFRET). Observation times of single FRET-labeled F(o)F(1)-ATP synthases in solution were extended up to several seconds using a confocal anti-Brownian electrokinetic trap (ABEL trap). By counting active versus inhibited enzymes, we revealed that ADP inhibition did not decrease the catalytic turnover of all F(o)F(1)-ATP synthases equally. Instead, increasing ADP in the ADP/ATP mixture reduced the number of remaining active enzymes that operated at similar catalytic rates for varying substrate/product ratios. MDPI 2023-05-08 /pmc/articles/PMC10178918/ /pubmed/37176150 http://dx.doi.org/10.3390/ijms24098442 Text en © 2023 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/). |
spellingShingle | Article Pérez, Iván Heitkamp, Thomas Börsch, Michael Mechanism of ADP-Inhibited ATP Hydrolysis in Single Proton-Pumping F(o)F(1)-ATP Synthase Trapped in Solution |
title | Mechanism of ADP-Inhibited ATP Hydrolysis in Single Proton-Pumping F(o)F(1)-ATP Synthase Trapped in Solution |
title_full | Mechanism of ADP-Inhibited ATP Hydrolysis in Single Proton-Pumping F(o)F(1)-ATP Synthase Trapped in Solution |
title_fullStr | Mechanism of ADP-Inhibited ATP Hydrolysis in Single Proton-Pumping F(o)F(1)-ATP Synthase Trapped in Solution |
title_full_unstemmed | Mechanism of ADP-Inhibited ATP Hydrolysis in Single Proton-Pumping F(o)F(1)-ATP Synthase Trapped in Solution |
title_short | Mechanism of ADP-Inhibited ATP Hydrolysis in Single Proton-Pumping F(o)F(1)-ATP Synthase Trapped in Solution |
title_sort | mechanism of adp-inhibited atp hydrolysis in single proton-pumping f(o)f(1)-atp synthase trapped in solution |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10178918/ https://www.ncbi.nlm.nih.gov/pubmed/37176150 http://dx.doi.org/10.3390/ijms24098442 |
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