TABLE III.
Simulation coefficients and parameters
| Symbol | Description | Reference value | Value used | Reference |
|---|---|---|---|---|
| cH,matrix | Bulk concentration of proton in matrix | pH 8.0 | 1×10−5 mol/m3 | [19] |
| cH,cyto | Bulk concentration of proton in cytosol | pH 7.2 | 1×10−4.2 mol/m3 | [19] |
| DHi | Diffusion coefficient of intracellular proton | 4×10−7–15.2×10−7 cm2/s | 10×10−7 cm2/s | [50] |
| DHmb | Diffusion coefficient of membrane-bound proton | 2×10−7–5.8×10−5 cm2/s | 1×10−5 cm2/s | [34, 39–44] |
| μ | Electric mobility of proton in medium | 28.7×10−4–35.9×10−4 cm2/(V s) | 30×10−4 cm2/(V s) | [51] |
| εIMS | Relative permittivity of the IMS | 80 | 80 | [52] |
| εIMM | Relative permittivity of the IMM | – | 5.647a | – |
| ρ0 | Average surface charge density at the P side | – | 1.5×10−3 C/m2b | – |
| ρATPase | Density of ATP synthase | – | 2500 molecules/μm2c | – |
| JH | Proton flux | 3100 H+/s/ATPase | 4.966×10−16 C/s/ATPase | [45] |
| EATP | Energy used to synthesize 1 mole of ATP | 14 kcal/mol | 58576 J/mol | [34] |
| D | Diameter of a crista junction | 20–40 nm | 30 nm | [4, 5, 49] |
| L | Length of a crista junction | 30–200 nm | 40 nm | [4, 53] |
a
εIMM is calculated by assuming that the capacitance of the IMM is 1 μF/cm2 and the IMM thickness (tIMM) is 5 nm. εIMM = (tIMM/ε0)×(1 μF/cm2) = 5.647, where ε0 is the electric constant.
b
ρ0 is calculated using the parallel plate capacitor model with a ΔΨm of −150 mV.
ρ0 = ε0εIMM×(Δϕ/tIMM) = 1.5×10−3 C/m2, where Δϕ is 150 mV.
c
ρATPase is calculated from the average distance between ATP synthases [54].
ρATPase = 1/(20 nm×20 nm) = 2500 molecules/μm2.