Figure 2
From: The molecular basis of thin filament activation: from single molecule to muscle
Ca++ affects the maximum force, duration and frequency of binding events from a mini-ensemble of myosin interacting with a regulated thin filament (RTF). (a) Cartoon of the mini-ensemble laser trap (not to scale). (b) Measured (black) and simulated (red) data, showing the force applied by the laser trap on one of the beads as a function of time. Binding events (shaded) are less frequent, shorter, and reach a smaller maximum force (hollow dot) at low Ca++ (pCa 7) than at high Ca++ (pCa 5). Inset shows how our custom event detection algorithm identifies maximum event force and lifetime. For these traces, trap stiffness was 0.0298 pN/nm (pCa 7) and 0.0382 pN/nm (pCa 5). ATP concentration is 100 μM.
