Table 1.

Model parameters

Quantity		Value	Comments
Potential periodicity, δ		2π/26	See (7,17).
Rotor drag coefficient, ζR		2 × 10−3 pN·nm·s/rad2	Estimated
Bead diffusion constant, DL		0.01–100 rad2/s	Calculated from Stokes' Law
Stator diffusion constant, Ds		500 rad2/s	Estimated
Load-rotor linkage spring constant, κ		400–500 pN·nm/rad2	Estimated from experimental measurements (49)
Saw-tooth potential height, U		10 kBT	Ad hoc
Ratio of the two potential branches, Lleft/Lright		1/9
Potential bumps	Height	15 kBT
	Width	0.2δ
	Centers	0.1δ (State1)
		0.6δ (State 2)
Transition windows	α1, α2	0.1δ, 0.6δ	Fitting data
	β1β2	0.58δ, (0.58 + 0.5)δ
Binding site pK value	H+ motor	pKa= 7.3	Estimated (using the middle value of external and internal concentrations)
	Chimera motor	pKa= 31.6 mM
Binding rate prefactors (two ions) k0	H+ motor	1.0 × 1020 s−1	Fit experimental torque-speed curve
	Chimera motor	1.0 × 108 s−1 (or 6.0 × 107 s−1 with a uniform window)
E. coli BFM living condition	pHperiplasm	7.0	Experimental values
	pHcytoplasm	7.6
	Vmembrane	120 mV
Chimera BFM living condition	[Na]periplasm	85 mM
	[Na]cytoplasm	12 mM
	Vmembrane	140 mV