Nonequilibrium fluctuations of lipid membranes by the rotating motor protein F1F0-ATP synthase

V.G. Almendro-Vedia , P. Natale , M. Mell , S. Bonneau , F. Monroy , F. Joubert , I. López-Montero

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Proceedings of the National Academy of Sciences of the United States of America
Published 10 Oct. 2017
DOI: 10.1073/pnas.1701207114


ATP synthase is a rotating membrane protein that synthesizes ATP through proton-pumping activity across the membrane. To unveil the mechanical impact of this molecular active pump on the bending properties of its lipid environment, we have functionally reconstituted the ATP synthase in giant unilamellar vesicles and tracked the membrane fluctuations by means of flickering spectroscopy. We find that ATP synthase rotates at a frequency of about 20 Hz, promoting large nonequilibrium deformations at discrete hot spots in lipid vesicles and thus inducing an overall membrane softening. The enhanced nonequilibrium fluctuations are compatible with an accumulation of active proteins at highly curved membrane sites through a curvature-protein coupling mechanism that supports the emergence of collective effects of rotating ATP synthases in lipid membranes.

This publication is related to:

Biomembrane plasticity and cellular function