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Updated: Aug 30, 2025

Purification of the Sarco-Endoplasmic Reticulum Ca2+-ATPase from Rabbit Muscle
Published on: March 21, 2025
Inhibition of SERCA and PMCA Ca2+-ATPase activities by polyoxotungstates
Manuel Aureliano1, Gil Fraqueza2, Maria Berrocal3
1FCT, Universidade do Algarve, 8005-139 Faro, Portugal; CCMar, Universidade do Algarve, 8005-139 Faro, Portugal.
Abstract:
Plasma membrane calcium ATPases (PMCA) and sarco(endo) reticulum calcium ATPases (SERCA) are key proteins in the maintenance of calcium homeostasis. Herein, we compare for the first time the inhibition of SERCA and PMCA calcium pumps by several polyoxotungstates (POTs), namely by Wells-Dawson phosphotungstate anions [P2W18O62]6- (intact, {P2W18}), [P2W17O61]10- (monolacunary, {P2W17}), [P2W15O56]12- (trilacunary, {P2W15}), [H2P2W12O48]12- (hexalacunary, {P2W12}), [H3P2W15V3O62]6- (trivanadium-substituted, {P2W15V3}) and by Preyssler-type anion [NaP5W30O110]14- ({P5W30}). The speciation in the solutions of tested POTs was investigated by 31P and 51V NMR spectroscopy. The tested POTs inhibited SERCA Ca2+-ATPase activity, whereby the Preyssler POT showed the strongest effect, with an IC50 value of 0.37 microM. For {P2W17} and {P2W15V3} higher IC50 values were determined: 0.72 and 0.95 microM, respectively. The studied POTs showed to be more potent inhibitors of PMCA Ca2+-ATPase activity, with lower IC50 values for {P2W17}, {P5W30} and {P2W15V3}.
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