The dithiol reagents phenylarsine oxide (PAO) and dibromobimane (DBrB) have opposite effects on the F1FO-ATPase activity. PAO 20% increases ATP hydrolysis at 50 μM when the enzyme activity is activated by the natural cofactor Mg2+ and at 150 μM when it is activated by Ca2+. The PAO-driven F1FO-ATPase activation is reverted to the basal activity by 50 μM dithiothreitol (DTE). Conversely, 300 μM DBrB decreases the F1FO-ATPase activity by 25% when activated by Mg2+ and by 50% when activated by Ca2+. In both cases, the F1FO-ATPase inhibition by DBrB is insensitive to DTE. The mitochondrial permeability transition pore (mPTP) formation, related to the Ca2+-dependent F1FO-ATPase activity, is stimulated by PAO and desensitized by DBrB. Since PAO and DBrB apparently form adducts with different cysteine couples, the results highlight the crucial role of cross-linking of vicinal dithiols on the F1FO-ATPase, with (ir)reversible redox states, in the mPTP modulation.

The mitochondrial F1FO-ATPase exploits the dithiol redox state to modulate the permeability transition pore

Algieri, Cristina
Primo
;
Trombetti, Fabiana;Pagliarani, Alessandra;Ventrella, Vittoria;Nesci, Salvatore
Ultimo
Supervision
2021

Abstract

The dithiol reagents phenylarsine oxide (PAO) and dibromobimane (DBrB) have opposite effects on the F1FO-ATPase activity. PAO 20% increases ATP hydrolysis at 50 μM when the enzyme activity is activated by the natural cofactor Mg2+ and at 150 μM when it is activated by Ca2+. The PAO-driven F1FO-ATPase activation is reverted to the basal activity by 50 μM dithiothreitol (DTE). Conversely, 300 μM DBrB decreases the F1FO-ATPase activity by 25% when activated by Mg2+ and by 50% when activated by Ca2+. In both cases, the F1FO-ATPase inhibition by DBrB is insensitive to DTE. The mitochondrial permeability transition pore (mPTP) formation, related to the Ca2+-dependent F1FO-ATPase activity, is stimulated by PAO and desensitized by DBrB. Since PAO and DBrB apparently form adducts with different cysteine couples, the results highlight the crucial role of cross-linking of vicinal dithiols on the F1FO-ATPase, with (ir)reversible redox states, in the mPTP modulation.
Algieri, Cristina; Trombetti, Fabiana; Pagliarani, Alessandra; Ventrella, Vittoria; Nesci, Salvatore
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11585/832412
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