Fig. 6: Mechanical power of cell division-like deformation is maximized during elongation. | Nature Communications

Fig. 6: Mechanical power of cell division-like deformation is maximized during elongation.

From: Mechanical power is maximized during contractile ring-like formation in a biomimetic dividing cell model

Fig. 6: Mechanical power of cell division-like deformation is maximized during elongation.

a Schematic showing the geometric parameters of a deforming liposome. The deforming liposome is approximated as two merged spheres. b Snapshots showing the initial and final frames of the deforming liposome. c The contour shape of the liposome extracted at each frame. Time is color-coded. d Mechanical energy of division-like deformation over time (n = 14 liposomes and N = 7 independent experiments). e Mechanical power calculated from (d) over time (n = 14 liposomes and N = 7 independent experiments). f Normalized power over shifted time. The individual time course for each liposome was normalized by the maximum power, \({P}_{{{{\rm{tot}}}}}^{\max },\) and the time is shifted by the time point, \({t}_{{P}_{{{{\rm{tot}}}}}^{\max }}\), at which the power reaches its maximum (n = 14 liposomes and N = 7 independent experiments). g Schematic showing the NADH-coupled assay used for myosin ATP hydrolysis rate measurements. First, ATP is regenerated from ADP with the conversion of PEP into pyruvate (pyr.) by PK. Then, NADH is oxidized to NAD+ with the conversion of pyruvate into lactate (lac.). The decay in NADH fluorescence mirrors the amount of ATP consumed. h Time-lapse images showing a deforming liposome with NADH fluorescence decay. i NADH fluorescence over time normalized by its initial value (n = 16 liposomes and N = 5 independent experiments in NADH only, n = 20 and N = 3 in actin only; n = 15 and N = 7 in dividing). j Total mechanical energy gain (\({\varDelta E}_{{{{\rm{tot}}}}}\)) and total free energy input (\(\varDelta {G}_{{{{\rm{ATP}}}}}\)) due to myosin ATP hydrolysis over time (n = 15 and N = 7). k Total mechanical power (\({P}_{{{{\rm{tot}}}}}\)) and free energy input rate (\({{{\rm{d}}}}{G}_{{{{\rm{ATP}}}}}/{{{\rm{d}}}}t\)) calculated from (j) over time (n = 15 liposomes and N = 7 independent experiments). l The fraction of energy gain (\({\eta }_{{{{\rm{gain}}}}}\)) and energy loss (\({\eta }_{{{{\rm{loss}}}}}\)) calculated from (k) (n = 15 liposomes and N = 7 independent experiments). Data are presented as mean ± SD (d–f, i–l). Scale bars, 10 μm. Source data are provided as a Source Data file.

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