Maria Ida De Michelis, Franca Rasi-Caldogno, Maria Chiara Pugliarello
{"title":"On the inhibiting effect of oligomycin on Mg: ATP-dependent ΔpH and Δψ in microsomal vesicles from radish","authors":"Maria Ida De Michelis, Franca Rasi-Caldogno, Maria Chiara Pugliarello","doi":"10.1016/0304-4211(84)90244-X","DOIUrl":null,"url":null,"abstract":"<div><p>The kinetics of inhibition by oligomycin of the mitochondrial ATPase and the Mg: ATP-dependent electrogenic transport of protons were compared in membrane preparations from radish seedlings.</p><p>Oligomycin blocks the phosphohydrolyzing activity of mitochondrial ATPase (measured at pH 8.5) at 1 μg × mg<sup>−1</sup> prot and the ATP-synthase one (measured at pH 6.6) at 3 μg × mg<sup>−1</sup> prot.</p><p>Oligomycin at these concentrations does not influence Mg: ATP-dependent proton transport and Mg: ATP-dependent hyperpolarization of transmembrane electric potential difference (PD) in microsomal vesicles. However, an inhibiting effect of the drug becomes apparent at concentrations higher than 10 μg × mg<sup>−1</sup> prot, increasing with the increase of oligomycin concentration at least up to 240 μg × mg<sup>−1</sup> prot. Both the vanadate and the NO<sub>3</sub><sup>−</sup>-sensitive systems of Mg: ATP-dependent electrogenic transport of protons show similar sensitivity to oligomycin.</p></div>","PeriodicalId":20221,"journal":{"name":"Plant Science Letters","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"1984-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0304-4211(84)90244-X","citationCount":"10","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Plant Science Letters","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/030442118490244X","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 10
Abstract
The kinetics of inhibition by oligomycin of the mitochondrial ATPase and the Mg: ATP-dependent electrogenic transport of protons were compared in membrane preparations from radish seedlings.
Oligomycin blocks the phosphohydrolyzing activity of mitochondrial ATPase (measured at pH 8.5) at 1 μg × mg−1 prot and the ATP-synthase one (measured at pH 6.6) at 3 μg × mg−1 prot.
Oligomycin at these concentrations does not influence Mg: ATP-dependent proton transport and Mg: ATP-dependent hyperpolarization of transmembrane electric potential difference (PD) in microsomal vesicles. However, an inhibiting effect of the drug becomes apparent at concentrations higher than 10 μg × mg−1 prot, increasing with the increase of oligomycin concentration at least up to 240 μg × mg−1 prot. Both the vanadate and the NO3−-sensitive systems of Mg: ATP-dependent electrogenic transport of protons show similar sensitivity to oligomycin.