Table 5.

Predicted Effect of Load on the ATPase Cycle when Actin Concentration is 3 $K_{\text{m}}$

	ATPase (s−1)	Detacheda	Weakly Attacheda	Strongly Attacheda	Duty Ratiob	Velocity (μm s−1)	Δ% AMDc	Δ% Velocityc	Δ% ATPasec
Fast Skeletal
[A] = 3 $K_{\text{m}}$	22.0896	0.3498	0.5382	0.1120	0.1120	0.9860
[A] = 3 $K_{\text{m}}$, loaded	8.5232	0.3130	0.5866	0.1004	0.1004	0.4245	15.75	−56.9	−61.4
HC WT β-S1
[A] = 3 $K_{\text{m}}$	4.4614	0.5655	0.3241	0.1103	0.1103	0.2021
[A] = 3 $K_{\text{m}}$, loaded	1.9720	0.4677	0.3930	0.1393	0.1393	0.0708	32.52	−64.9	−55.7
HC WT α-S1
[A] = 3 $K_{\text{m}}$	13.5034	0.3820	0.4676	0.1504	0.1504	0.4489
[A] = 3 $K_{\text{m}}$, loaded	5.1737	0.3305	0.5082	0.1612	0.1612	0.1605	14.94	−64.2	−61.4
HC R453C β-S1
[A] = 3 $K_{\text{m}}$	3.7525	0.5769	0.2468	0.1763	0.1763	0.1064
[A] = 3 $K_{\text{m}}$, loaded	1.6619	0.4714	0.3003	0.2283	0.2283	0.0364	32.84	−65.7	−55.7

^aFractional occupancy for the detached, weakly attached, and strongly attached states.

^bRatio of strongly attached myosins to total myosin heads.

^cPercent change in the parameter upon applying a load.