= Work of a spatially gated myosin head
{title2=$W=\kappa p_b[x_0^2/2-(v/k_{off})^2]$}
For attached-state <elastic energy> $U=\kappa(x-x_0)^2/2$ and a binding window much narrower than $x_0$, the expected assisting work before $x_0$ is $\kappa p_bx_0^2/2$. The detachment tail produces resisting work $-\kappa p_bv^2/k_{off}^2$. Mean <force> per head is $W/D$ for site spacing $D$. The detachment-time second moment, not the square of its mean, fixes the resisting term. These are idealized prescribed-velocity kinetics, not a complete muscle energy budget.
Back to article page
