Inhibition of Yeast Plasma-membrane H+-atpase By Fluoroaluminates
(1994) BBA. Bioenergetics — Vol. 1184, n° 1, p. 127-133 (1994)
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- The mechanism of inhibition of the Schizosaccharomyces pombe plasma membrane H+-ATPase by fluoroaluminates has been investigated. A biphasic inhibitory process was observed at pH 7.5, with a preference for the AlF4- species. The dissociation constant found for AlF4- is 8.5 mu M, Mg2+ being an essential cofactor for the inhibition. The rate constant of the rapid inhibition phase is decreased at pH values lower than 7.0 which may reveal a preferential action of AlF4- on the E(2) conformation of the enzyme. The slow phase of inhibition was found to be quasi-irreversible and highly dependent on the water activity. This dependence was studied by adding Me(2)SO in the solvent and can be explained by the release of five water molecules upon fluoroaluminate binding. It is proposed that inhibition of the H+-ATPase is due to the formation of a stable E(2)-Mg-AlF4 complex analog to the phosphorylated intermediate of the H+-ATPase.
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Rapinlegroux, C., Troullier, A., Dufour, JP., & Dupont, Y. (1994). Inhibition of Yeast Plasma-membrane H+-atpase By Fluoroaluminates. BBA. Bioenergetics, 1184(1), 127-133. https://doi.org/10.1016/0005-2728(94)90162-7 (Original work published 1994)