pyrene labelled muscle actin  (Cytoskeleton Inc)

Journal: bioRxiv

Article Title: Mechanical organization yields degenerate dissipation beyond linear response

doi: 10.64898/2026.04.22.720181

Figure Lengend Snippet: (a) Schematic of pseudo-2D actomyosin network crowded by Methylcellulose on the lipid bilayer. (b) Confocal fluorescence microscopy image of pseudo-2D actomyosin network crosslinked by fascin (top) and α-actinin (bottom) on a supported lipid bilayer. Left is before crosslinking, and right is post crosslinker addition. Scalebar is 5 µm. (c) Kymograph of the yellow dashed line in b), scalebars are 5µm (horizontal) and 10s (vertical). (d) Exemplary linescan intensity (normalized) for conditions in e. (e) Bundling metric λ of fascin and α-actinin crosslinked networks as well as F-actin network without crosslinkers. N = 3 for each condition. (f) Exemplary autocorrelation function of actin network fluctuations as function of lag time Δ t . (g) Characteristic time τ for different conditions. N = 5,3,3,3,3,3 respectively. (h) Confocal fluorescence microscopy image of 2D actomyosin network crosslinked by fascin (top) and α-actinin (bottom) deformed and contracted under myosin active stress over time. Scalebars are 20 µm. Heatmaps show accumulative strain of the final frame. Quiver plot overlay shows the instantaneous velocity. (i) Kymograph of α-actinin network rupture (dashed red line in h). Scalebars are 10µm and 10s. (j) Mean strain < ε > of the network during deformation caused by myosin induced active stress over time. The slope of the strain curve is the strain rate (k) Maximum mean strain < ε > max of fascin and α-actinin crosslinked networks at R c = 0.2. N = 3 for each condition. p fas − aa = 0.0101. (l) Strain rate of the network crosslinked by α-actinin at R c = 0.1 at various myosin concentrations. N = 2,3,3,3,2,2,2 from low to high concentration respectively.

Article Snippet: Dark G-actin (Cytoskeleton) is mixed with rhodamine labelled F-actin (20% fluorescent, Cytoskeleton) to a final molar concentration of 1.4 μM, and is stabilized with 1 μM phalloidin (Cytoskeleton) and crowded to the surface of a 97% Egg Phosphatidyl Choline (Avanti Polar Lipids)/3% FITC-DHPE (Molecular Probes) phospholipid bilayer, using 0.2% 14,000 MW methyl-cellulose (Sigma, 15 cP) as a depletion agent ( ).

Techniques: Fluorescence, Microscopy, Concentration Assay