Kinetic properties of the mitochondrial F1FO-ATPase activity elicited by Ca(2+) in replacement of Mg(2).

TitleKinetic properties of the mitochondrial F1FO-ATPase activity elicited by Ca(2+) in replacement of Mg(2).
Publication TypeJournal Article
Year of Publication2017
AuthorsNesci, S, Trombetti, F, Ventrella, V, Pirini, M, Pagliarani, A
JournalBiochimie
Volume140
Pagination73-81
Date Published2017 Sep
ISSN1638-6183
KeywordsAnimals, Calcium, Dicyclohexylcarbodiimide, Magnesium, Membrane Potential, Mitochondrial, Mitochondria, Heart, Oligomycins, Proton-Translocating ATPases, Swine
Abstract

The mitochondrial F-ATPase can be activated either by the classical cofactor Mg(2+) or, with lower efficiency, by Ca(2+). The latter may play a role when calcium concentration rises in mitochondria, a condition associated with cascade events leading to cell death. Common and distinctive features of these differently activated mitochondrial ATPases were pointed out in swine heart mitochondria. When Ca(2+) replaces the natural cofactor Mg(2+), the enzyme responsiveness to the transmembrane electrochemical gradient and to the classical F-ATPase inhibitors DCCD and oligomycin as well as the oligomycin sensitivity loss by thiol oxidation, are maintained. Consistently, the two mitochondrial ATPases apparently share the F1FO complex basic structure and mechanism. Peculiar cation-dependent properties, which may affect the F1 catalytic mechanism and/or the FO proton binding site features, may be linked to a different physiological role of the mitochondrial Ca-activated F-ATPase with respect to the Mg-activated F-ATPase.

DOI10.1016/j.biochi.2017.06.013
Alternate JournalBiochimie
Citation Key10.1016/j.biochi.2017.06.013
PubMed ID28652018