FIGURE 3.

Stiffness of the F₁ in ADP-inhibition and ϵ-inhibition. A and B, histograms of angular position of the 340-nm duplex beads at 250 nm ATP (red), in ADP-inhibition (blue in A) or in ϵ-inhibition (green in B). Both the stop angular positions of the γ subunit inhibited at ADP-inhibited form and by the ϵ subunit were 80° forward from that for ATP binding. The fluctuations of the beads in ADP-inhibition or ϵ-inhibition were observed for 30 s with a 2-ms time resolution. C, probability distribution of the fluctuation of the beads in ADP-inhibition (blue) and ϵ-inhibition (green) fitted using a single Gaussian function. The stiffness of the γ subunit, κ, was calculated from the equation: σ² = k_BTκ⁻¹, where σ² is a variance from Gaussian distribution as described (39).